Home Zwitterion coordination to configurationally flexible d 10 cations: synthesis and characterization of tetrakis(betaine) complexes of divalent Zn, Cd, and Hg
Article Publicly Available

Zwitterion coordination to configurationally flexible d 10 cations: synthesis and characterization of tetrakis(betaine) complexes of divalent Zn, Cd, and Hg

  • Steven van Terwingen ORCID logo , Léana Wendland , Irmgard Kalf , Holger Fränzl and Ulli Englert ORCID logo EMAIL logo
Published/Copyright: September 20, 2021
Download Article (PDF)
Become an author with De Gruyter Brill
Author Information Explore this Subject
Zeitschrift für Naturforschung B
From the journal Zeitschrift für Naturforschung B Volume 76 Issue 10-12

Abstract

The d 10 ions MII (M = Zn, Cd, Hg) and four equivalents of the neutral zwitterion trimethylglycine (betaine, bet) aggregate to discrete six-coordinated cationic complexes. With nitrate as counter anions, solids of the composition [M(bet)4](NO3)2·H2O are obtained. Their structural characterization reveals close relationship: they crystallize in metrically similar unit cells adopting three different subgroups of a hypothetical aristotype. In all cases, the divalent cations exhibit a strongly distorted coordination sphere in which two betaine ligands bind with both carboxylato O atoms and the other two with only one oxygen to the cation. Non-coordinating O atoms of different betaine ligands act as hydrogen bond acceptors towards co-crystallized water molecules. At least for the Pearson-soft HgII cations, this coordination is unexpected: to the best of our knowledge, HgII complexes with four carboxylato ligands have not yet been characterized. Without the necessity for charge balancing, the composition of zwitterion complexes is dominated by steric requirements and possibly by competition with alternative dipole molecules such as solvent water.

Keywords: betaine coordination; d 10 complexes; pseudosymmetry

1 Introduction

Carboxylates and their derivatives count among the most popular ligands in coordination chemistry: the Cambridge Structural Database (CSD) [1] contains almost 400,000 well-ordered and error-free compounds with at least one metal in the atom list and for which 3D coordinates are available; 73,000 among these are metal-coordinated carboxylates. Complexes of α-amino acids are less frequent than carboxylates in general but still rather common, with more than 9000 matching structures [2,3]. Our group has explored the coordination abilities of the amino acids alanine [4], valine [5] and in particular proline [6], [7], [8], [9], [10]. In contrast to the abundant literature on amino acids, the N permethylated derivative of glycine has been scarcely used as a coordination partner. Trimethylglycine, also known as betaine because of its natural occurence in sugar beet (Beta vulgaris L.) [11], represents a prototypic zwitterion. It combines an anionic carboxylato moiety with a quaternary ammonium cation in an overall neutral molecule. Independent of the basicity of the reaction medium and different from amino acids, the betaine N atom does not exhibit any nucleophilic properties.

Sixty coordination compounds of trimethylglycine have been structurally characterized, and in only five of these, the entire coordination sphere about the metal cation stems from betaine without any additional co-ligands [12], [13], [14], [15], [16], [17], [18]. We expected that coordination complexes with a high content of betaine should be readily accessible because the stoichiometry-limiting aspects of charge balance do not apply. In order to accommodate even an irregular coordination sphere, we decided to focus our initial work on complexes with d 10 cations, devoid of any crystal field stabilization [19]. In this contribution, we report the synthesis and characterization of group 12 betaine nitrates; Figure 1 summarizes the reaction conditions and composition of the target products.

Figure 1: The tetrakis(betaine) complexes of the group 12 metal nitrates can be synthesized either in aqueous solution or by grinding: M = Zn (1), Cd (2), Hg (3).
Figure 1:

The tetrakis(betaine) complexes of the group 12 metal nitrates can be synthesized either in aqueous solution or by grinding: M = Zn (1), Cd (2), Hg (3).

2 Results and discussion

The target compounds 1–3 are readily available via reaction of the metal nitrates with the required four equivalents of betaine in water. Slow evaporation of the solvent results in apparently very beautiful crystals (Figure 2, Figures S3–S5).

Microanalytical data for the Zn and Cd derivative supported the expected composition with four betaine residues per metal cation. Powder diffraction confirmed the crystallinity of all compounds 1–3 and suggested close structural relationship (Figure 3).

Figure 2: Crystals of 1 and 3 obtained by slow evaporation of solvent from aqueous solution at ambient temperature. Yellow traces of HgO can be observed for 3.
Figure 2:

Crystals of 1 and 3 obtained by slow evaporation of solvent from aqueous solution at ambient temperature. Yellow traces of HgO can be observed for 3.

Figure 3: Synopsis of the X-ray powder patterns for 1 (black), 2 (blue) and 3 (red).
Figure 3:

Synopsis of the X-ray powder patterns for 1 (black), 2 (blue) and 3 (red).

2.1 Challenges in single crystal diffraction

We will first focus on aspects of space group symmetry and packing; a comparison between the [M(bet)4]2+ cations will be provided in Subsection 2.3.

Crystals of all three compounds show a strong tendency to twinning; indexing of their diffraction patterns required two rather than a single orientation matrix. Figure 4 shows that rotation of the diffraction pattern about the reciprocal lattice parameter c * results in “almost” overlapping reflections.

Figure 4: Twinning in 1–3; unit cells for the two domains are drawn in black and blue, the twin law corresponds to rotation about c *.
Figure 4:

Twinning in 1–3; unit cells for the two domains are drawn in black and blue, the twin law corresponds to rotation about c *.

Integration of the diffraction data was challenging in all cases, and our final structure models are associated with unsatisfactory agreement factors and high residual electron density. The systematic intergrowth in crystals of 1–3 does not only affect structure solution and refinement but also precludes a straightforward determination of their space groups based on systematic extinctions: the twin law shown in Figure 4 approximately relates two alternative settings of the monoclinic space groups with a glide plane; we will come back to this aspect below.

Twinning apart, all structures of 1–3 show pronounced pseudosymmetry, with independent cations on pseudo-special positions. The inter-cation vectors are characterized by Δx, Δy and Δz components of approx. 0.0 or 0.5. Consequently, all three diffraction patterns appear as pseudo-centered, with ratios I (hkl), h + k = 2n/I (hkl), h + k = 2n + 1 = 1.4 (Zn), 2.3 (Cd) and 2.5 (Hg). For obvious contrast reasons, the pseudosymmetry is most pronounced when the many-electron scattering centers Hg are involved.

Our attempt to isolate untwinned crystals were not successful. In the case of 2, the subset of relatively intense reflections commonly used for indexing of the diffraction pattern could be interpreted with a single orientation matrix. Inspection of the h0l reflections revealed, however, that even in this case a large number of in principle extinct reflections with l = 2n were detected with significant intensities. We remind the reader of the twin law explained in Figure 4 and the fact that the alternative settings for the glide plane are exchanged by the twin law. A second twin domain, rather small in the case of 2, could thus be detected.

2.2 Packing and symmetry relationship

A third surprising feature of the crystal structures could only be detected after successful structure solution and refinement. Despite the similarity in their powder patterns and their analogous composition, 1–3 are not isomorphous. Rather, their relationship may be explained with the help of the Bärnighausen tree [20,21] in Figure 5.

Figure 5: Structural relationship between 1 and 3. Packing diagrams represent projections on the (1 0 1) plane. The cationic tetrakis(betaine) complexes are shown as green spheres, the nitrate counter anions as blue spheres.
Figure 5:

Structural relationship between 1 and 3. Packing diagrams represent projections on the (1 0 1) plane. The cationic tetrakis(betaine) complexes are shown as green spheres, the nitrate counter anions as blue spheres.

Our assignment of the aristotype at the top of the Bärnighausen tree as “hypothetical” deserves a comment. At ambient temperature, the diffraction pattern of a crystal of 3 could be indexed assuming a C centered monoclinic unit cell, thus matching the aristotype symmetry in Figure 5. In this high temperature symmetry, the asymmetric unit contains a single HgII cation, but the rather soft coordination environment about HgII and the presence of mobile groups which may librate about their position ( NO 3 − , NMe3) precludes free refinement of a structure model at atomic resolution. The underlying intensity data and the associated structure model do not meet our own standards for publication, but help to understand the powder pattern of 3 at room temperature. Figure 6 shows the good match between this simulation based on the incomplete structure model for the aristotype (blue) and two experimental patterns; the diffractogram depicted in red was obtained on crystals only ground for a few seconds, the one in black on rigorously ground crystalline material of 3. The latter is associated with a higher amorphous background, but grinding also alleviates the effect of preferred orientation, with much more realistic intensities.

Figure 6: Powder pattern for the aristotype in space group C2/c. Simulation based on an incomplete structure model (blue) and experimental patterns after very short (red) and prolonged (black) grinding.
Figure 6:

Powder pattern for the aristotype in space group C2/c. Simulation based on an incomplete structure model (blue) and experimental patterns after very short (red) and prolonged (black) grinding.

The powder pattern in Figure 6 suggests that 3 adopts the C2/c aristotype structure at room temperature, but we cannot provide conclusive evidence based on single-crystal diffraction for this statement. Despite significant differences in the tetrakis(betaine) cations which will be discussed in Subsection 2.3, 1–3 share common packing features. In each cation, two carboxylato O atoms are located at much longer M⋯O separations than the other oxygen atoms. These more peripheral O atoms act as hydrogen bond acceptors towards the H atoms of the co-crystallized water molecules. Figure 7 shows the resulting infinite chain along [1 0 0] for the example of 3; very similar arrangements are observed for 1 and 2.

Figure 7: Hydrogen bonded chain along [1 0 0] involving the tetrakis(betaine) cations and the co-crystallized water molecules. Symmetry operators: i = 1 − x, 1/2 + y, 1/2 − z; ii = 1 + x, y, z; iii = −x, 1/2 + y, 1/2 − z; iv = −1 + x, y, z.
Figure 7:

Hydrogen bonded chain along [1 0 0] involving the tetrakis(betaine) cations and the co-crystallized water molecules. Symmetry operators: i = 1 − x, 1/2 + y, 1/2 − z; ii = 1 + x, y, z; iii = −x, 1/2 + y, 1/2 − z; iv = −1 + x, y, z.

In the case of 3, donor⋯acceptor distances for the classical O–H⋯O bonds subtending the chains range between 2.88 and 2.95 Å. Another common aspect of 1–3 should be explained to avoid any misinterpretation which might arise from Figure 5. In this figure, only centers of gravity have been shown. A more realistic representation with respect to dimensions is provided in Figure 8.

Figure 8: Space filling projection along b of the [Hg(bet)4]2+ cations in the unit cell of 3. Voids in the range of approx. 45 Å3 containing the nitrate counter anions are shown as yellow spheres.
Figure 8:

Space filling projection along b of the [Hg(bet)4]2+ cations in the unit cell of 3. Voids in the range of approx. 45 Å3 containing the nitrate counter anions are shown as yellow spheres.

Figure 8 shows that the large tetrakis(betaine) cations with their 33 non-hydrogen atoms clearly dominate the packing and touch in their methylated periphery; the much smaller nitrate anions are accommodated in voids of approx. 45 Å3.

2.3 Comparison of the tetrakis(betaine) cations

Despite the limitations outlined in Subsection 2.1, structure models at atomic resolution are available for the low temperature forms of 1–3 and the [M(bet)4]2+ complexes in these solids may be compared. A full compilation of the coordination geometry for the two independent cations in 1 and 3 and the four independent cations in 2 is available in the Supplementary material, Tables S2 and S3. We here summarize the trends. The oxygen coordination about the Zn2+ cations in 1 (Figure 9a) may best be described as 4 + 2. Each carboxylato moiety binds to the metal atom with one short Zn–O bond of approx. 2.0 Å. The chelating betaine ligands adopt an asymmetric coordination with two substantially longer (2.5–2.6 Å) interactions Zn1–O3 and Zn1–O4. The carboxylato oxygen atoms O6 and O8 of the mono-hapto betaine ligands remain uncoordinated, with Zn⋯O of approx. 3.2 Å.

Figure 9: Ball-and-stick representation [22] of the coordination spheres around a) Zn1 in 1 and b) Hg1 in 3. Range of M⋯O contacts: Zn1 1.971(10)–3.221(9) Å; Hg1 2.226(7)–3.096(7) Å.
Figure 9:

Ball-and-stick representation [22] of the coordination spheres around a) Zn1 in 1 and b) Hg1 in 3. Range of M⋯O contacts: Zn1 1.971(10)–3.221(9) Å; Hg1 2.226(7)–3.096(7) Å.

The distance pattern about the divalent Cd ions in 2 is less clear-cut; in particular, the two chelating betaine moieties about each Cd center show an almost symmetric arrangement. One of the independent [Hg(bet)4]2+ cations is depicted in Figure 9b. In 3, the softness of the HgII ion leads to an overall more narrow range of eight Hg⋯O contacts. According to the bond valence concept [23], the mercury centers are still perceived as six-coordinated, but the difference between the shortest M−O bond and the longest M⋯O non-bonded contact amounts to 0.87 Å and is substantially smaller than in the case of ZnII (1.2 Å).

The eight independent [M(bet)4]2+ cations in 1–3 share a common feature: their coordination spheres are highly distorted and cannot be described with regular polyhedra. What does “distorted” mean in the first place? Often this concept is referred to as a change in shape of a body as a result of an outer force. In chemistry, we usually use the term “distorted” to describe the discrepancy between the system under study and a regular polyhedron.

Several arguments favor regular polyhedra in chemistry. The steric demand of the peripheral groups and repulsion between valence electrons around a central atom dominate the arrangement about main group elements. Typical examples for tetrahedral geometry are tetraphenylphosphonium tetraphenylborate PPh4BPh4 (CCDC [1] refcode ROPNEP [24]) or tetraphenylarsonium periodate AsPh4IO4 (SOVYIL [25]). Regular octahedral coordination can be encountered in association with tetrahedral geometry, e. g. in tetraphenylphosphonium hexabromidouranate PPh4UBr6 (GAGVOZ [26]), in which the UV cation is surrounded by six bromido ligands in an octahedral fashion. Moving to transition metal centers, the important factor ligand-field stabilization has to be taken into account. It can stabilize orthogonal over irregular coordination geometries and in particular favor octahedra: in the d 6 complex [Cr(CO)6] (FOHCOU10 [27]) the carbonyl ligands form an almost perfect octahedron around the central Cr0 atom, although the crystallographically imposed symmetry is only m. Ligand-field arguments may, however, also result in still orthogonal but distorted polyhedra: the Jahn-Teller effect describes the compression or elongation of the axial ligands in transition metal complexes. Its consequences are very pronounced in d 9 CuII complexes, e. g. in hexaaquacopper(II) p-chlorobenzenesulfonate (SIYZIJ [28]), in which the equatorial aqua ligands exhibit much shorter distances towards the central ion than the axial ones (1.95 vs. 2.42 Å). To the best of our knowledge, six-fold oxygen coordination to HgII by carboxylato ligands is unprecedented. Charge balance may be the limiting factor for most carboxylates which obviously does not concern betaine coordination. Octahedral coordination to HgII by other oxygen donors have rarely been reported, e. g. for hexakis(dimethylsulfoxido)mercury(II) triflate [Hg(DMSO)6](OTf)2 (ZAMGEZ [29]) or hexakis(pyridine-N-oxido)mercury(II) perchlorate [Hg(Py–O)6](ClO4)2 (PYOHPG01 [30]); almost regular octahedra are formed in these cases, very much in contrast to the situation in 3.

How to quantify distorsion in such irregular polyhedra like the [M(bet)4]2+ cations? Robinson et al. [31] have identified two main modes of distorsion: they considered angular variation (AV) at constant metal-ligand distances which might distort a regular octahedron to a regular trigonal prism and quadratic elongation (QE), corresponding to the variation of distances in (unmodified) orthogonal geometry according to these equations:

(1) AV oct = 1 11 ∑ i = l 12 ( θ i − 90 ∘ ) 2

θ i : octahedral angle i ligand–central–ligand/°.

(2) QE oct = 1 6 ∑ i = 1 6 ( l i l 0 ) 2

l i : length of ligand i to the central atom/Å.

l 0: length of ligand to the central atom for an O h octahedron with the same volume as the present system/Å.

For many structurally characterized six-coordinated polyhedra the value for QE varies within rather narrow limits between 1.00 in regular octahedra and 1.07 in Jahn-Teller distorted complexes, while the angle variance shows wider spread between 0 and even >200. Both AV and QE may easily be calculated with the Platon software [22]. For our compounds 1–3, both AV and QE assume impressively large values; their synopsis has been compiled in Table 1, together with the chemically intuitive examples mentioned above.

Table 1:

Quadratic elongation (QE) and angle variance (AV) for compounds 1–3 and in selected reference structures.

1 2 3
QE/a.u. 1.140 1.145 1.238
AV/°2 353 420 612
[Cr(CO)6] [27] [Cu(OH2)6] 2+ [28] [Hg(DMSO)6] 2+ [29]
QE/a.u. 1.000 1.025 1.007
AV/°2 0 13 23

The numerical values in Table 1 confirm the strong distortion of the MO6 polyhedra but also reflect the increasing cation radius: a large contribution to the angle variance is caused by the invariably acute bite angle of the two chelating betaine ligands. This deviation from regular geometry increases with the radius of the central cation.

One might intuitively expect to extract structural information from the IR spectra for 1–3: the difference in wavenumbers between the asymmetric and symmetric vibration in a RCOO− group can in principle help to address a coordinated carboxylate as terminal (monodentate), bridging or chelating (bidentate). The situation here is rather complicated: 1 and 3 contain 8, 2 even 16 symmetrically independent betaine moieties, part of them in monodentate, others in bidentate coordination mode. Bidentate carboxylates with two strongly different M–O cannot be distinguished from terminal ones [32]. An additional complication arises because both ν ˜ a and ν ˜ s of the betaine ligands overlaps with the strongest vibrations of the (again many!) symmetrically independent nitrate counter anions. As a result, the IR spectra of 1 - 3 exhibit many vibrations in the range 1700–1300 cm−1. The spectra for all three compounds are rather similar and have been depicted in the SI (Figure S2). Based on these spectra, we can only exclude a dominant occurence of symmetrically chelating betaine ligands.

3 Conclusions

Despite the differences addressed above, the mere existence of the cationic [M(bet)4]2+ complexes M = Zn, Cd and Hg, i.e. for all group 12 elements, is surprising. Divalent Zn represents a notoriously small cation and has been ranked as borderline with respect to Pearson hardness [33], whereas HgII is substantially larger [34] and classified as soft. We conclude that betaine represents a very promising ligand for a wide range of cations. Its electroneutrality allows for different stoichiometries, almost comparable to “hydration”. Tests for interesting solids and potential structural relationships will be facilitated by performing mechanochemical reactions. We will extend our studies to complexes of the less toxic divalent alkaline earth cations and of the lanthanides. Similar to the Zn derivative 1 reported here, their less toxic representatives represent attractive targets for a joint venture between laboratories at a university and a secondary school.

4 Experimental

4.1 Materials and methods

All chemicals were used without further purification. Infrared spectra were measured using a Nicolet Avatar 360 E.S.P. spectrometer in potassium bromide windows. Elemental analyses were performed using a Heraeus CHNO-Rapid VarioEL. Powder diffraction experiments were recorded on flat samples at room temperature using a STOE STADI-P diffractometer with Guinier geometry (Cu-K α1, λ = 1.54059 Å, Johann germanium monochromator, STOE image plate detector IP-PSD, 0.005 step width in 2θ). Intensity data for 1 and 3 was collected with a Bruker D8 goniometer equipped with an APEX CCD area detector and an Incoatec microsource (Mo-K α radiation, λ = 0.71073 Å, multilayer optics) with an Oxford Cryostream 700 (Oxfordshire, UK) for temperature control and for 2 intensity data was collected with a STOE STADIVARI goniometer with a Dectris Pilatus 200 K area detector equipped with a GeniX 3D HF Mo microsource (Mo-K α radiation, λ = 0.71073 Å, multilayeroptics) with an Oxford Cryostream 800 (Oxfordshire, UK) for temperature control. Data was integrated with saint [35] (1, 3) and corrected for absorption by multi-scan methods with sadabs [36] (1, 3) and for 2 data was integrated with X-Area [37] and corrected for absorption with lana [38]. The structures were solved by intrinsic phasing [39] and refined by full matrix least squares procedures against F 2, as implemented in shelxl-18 [40]. Crystal data, data collection parameters and convergence results have been compiled in Table S1.

4.2 Synthetic procedures

[Zn(bet) 4 (NO 3 ) 2 ]·H 2 O, 1: Zinc nitrate hexahydrate (1.111 g, 3.73 mmol) and betaine (2.000 g, 17.1 mmol) were dissolved in water (1 mL) and the mixture was heated to 75 °C for 4–6 h. Then, the solution was let unperturbed for slow evaporation at room temperature. After approx. two to three weeks crystals started forming. After formation of at least 10 mg of crystalline material, the solid was removed from the mother liquor and characterized by microanalysis and powder diffraction. This procedure was repeated until no further crystals formed. Yield: quant. The dried bulk material corresponds to the monohydrate: C20H44N6O14Zn·H2O (676.0): calcd. C 35.5%, H 6.8%, N 12.4%; found: C 35.7%, H 6.7%, N 12.4% – M.p. 245 °C.

[Cd(bet) 4 (NO 3 ) 2 ]·H 2 O, 2: The same procedure as for 1 was applied with cadmium nitrate tetrahydrate (1.144 g, 3.71 mmol) and betaine (2.000 g, 17.1 mmol). After approx. four weeks crystals started forming. Yield: quant. The dried bulk material corresponds to the monohydrate: C20H44N6O14Cd·H2O (723.0): calcd. C 33.2%, H 6.4%, N 11.6%; found: C 32.9%, H 6.5%, N 11.3% – M.p. 260 °C.

[Hg(bet) 4 (NO 3 ) 2 ]·H 2 O, 3: A modified procedure as for 1 was applied with mercury(II) nitrate monohydrate (1.456 g, 4.25 mmol) and betaine (2.000 g, 17.1 mmol). After mixing, traces of two different crystal forms of HgO (s. Figure 2 and Figure S1, corresponding to the structure types HgS [41] and HgO [42]) were removed by filtration. The onset of crystallization was observed after two weeks. Yield: >90%. M.p. 212 °C. The bulk material could not be analyzed by microanalysis because our department does not provide combustion analysis for mercury containing compounds.

Mechanochemical route: Zinc nitrate hexahydrate (1.111 g, 3.73 mmol) and betaine (2.000 g, 17.1 mmol) were ground in a mortar for 1 min. The mixture immediately became viscous and was subsequently dried at 100 °C for several hours. Samples for analysis were taken every two days.

CCDC 2099213–2099215 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

5 Supporting information

Further crystal data and refinement results, powder diffraction diffractograms, IR spectra, and additional crystal images are given as supplementary material available online. (https://doi.org/10.1515/znb-2021-0101).

Dedicated to: Professor Richard Dronskowski of the RWTH Aachen on the occasion of his 60th birthday.

Corresponding author: Ulli Englert, Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, Germany; and Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, People’s Republic of China, E-mail:

Acknowledgment

S.v.T. acknowledges an RWTH fellowship for doctoral students.

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: None declared.

  3. Conflict of interest statement: The authors declare no conflicts of interest regarding this article.

References

1. Groom, C. R., Bruno, I. J., Lightfoot, M. P., Ward, S. C. Acta Crystallogr. 2016, B72, 171–179; https://doi.org/10.1107/s2052520616003954.Search in Google Scholar

2. Severin, K., Bergs, R., Beck, W. Angew. Chem. Int. Ed. 1998, 37, 1634–1654; https://doi.org/10.1002/(sici)1521-3773(19980703)37:12<1634::aid-anie1634>3.0.co;2-c.10.1002/(SICI)1521-3773(19980703)37:12<1634::AID-ANIE1634>3.0.CO;2-CSearch in Google Scholar

3. Shimazaki, Y., Takani, M., Yamauchi, O. Dalton Trans. 2009, 7854–7869; https://doi.org/10.1039/b905871k.Search in Google Scholar

4. Lamberts, K., Möller, A., Englert, U. Acta Crystallogr. 2014, B70, 989–998; https://doi.org/10.1107/s2052520614021398.Search in Google Scholar

5. Lamberts, K., Englert, U. Crystals 2015, 5, 261–272; https://doi.org/10.3390/cryst5020261.Search in Google Scholar

6. Lamberts, K., Englert, U. Acta Crystallogr. 2012, B68, 610–618; https://doi.org/10.1107/s0108768112043996.Search in Google Scholar

7. Lamberts, K., Porsche, S., Hentschel, B., Kuhlen, T., Englert, U. CrystEngComm 2014, 16, 3305–3311; https://doi.org/10.1039/c3ce42357c.Search in Google Scholar

8. Lamberts, K., Şerb, M.-D., Englert, U. Acta Crystallogr. 2015, C71, 271–275; https://doi.org/10.1107/s205322961500426x.Search in Google Scholar

9. Lamberts, K., Şerb, M.-D., Englert, U. Acta Crystallogr. 2015, C71, 311–317; https://doi.org/10.1107/s2053229615005008.Search in Google Scholar

10. Lamberts, K., Tegoni, M., Jiang, X., Kou, H.-Z., Englert, U. Dalton Trans. 2016, 45, 284–295; https://doi.org/10.1039/c5dt03749b.Search in Google Scholar

11. Lee, E. J., An, D., Nguyen, C. T. T., Patil, B. S., Kim, J., Yoo, K. S. J. Agric. Food Chem. 2014, 62, 1324–1331; https://doi.org/10.1021/jf404648u.Search in Google Scholar

12. Chen, X.-M., Mak, T. C. W. Inorg. Chim. Acta 1991, 189, 3–5.10.1016/S0020-1693(00)80380-1Search in Google Scholar

13. Schreuer, J., Haussühl, S. Z. Kristallogr. 1993, 205, 309–310; https://doi.org/10.1524/zkri.1993.205.part-2.309.Search in Google Scholar

14. Yang, Y.-Y., Chen, X.-M., Ng, S. W. Acta Crystallogr. 2002, E58, m61–m62; https://doi.org/10.1107/s1600536802001459.Search in Google Scholar

15. Wiehl, L., Schreuer, J., Haussühl, E. Z. Kristallogr. NCS 2006, 221, 77–79; https://doi.org/10.1524/ncrs.2006.221.1.77.Search in Google Scholar

16. Kocadag, M., Fleck, M., Bohatý, L. Acta Crystallogr. 2008, E64, m1273–m1274; https://doi.org/10.1107/s1600536808028912.Search in Google Scholar

17. Haussühl, E., Wiehl, L., Schreuer, J. Z. Kristallogr. NCS 2009, 224, 33–34; https://doi.org/10.1524/ncrs.2009.224.14.33.Search in Google Scholar

18. Haussühl, E., Wiehl, L., Schreuer, J. Z. Kristallogr. NCS 2009, 224, 35–36; https://doi.org/10.1524/ncrs.2009.224.14.35.Search in Google Scholar

19. Kremer, M., Englert, U. Acta Crystallogr. 2019, E75, 903–911; https://doi.org/10.1107/s2056989019007461.Search in Google Scholar

20. Bärnighausen, H. MATCH 1980, 9, 139–175.10.1016/0002-9610(80)90249-4Search in Google Scholar

21. Müller, U. Symmetry Relationships Between Crystal Structures: Applications of Crystallographic Group Theory in Crystal Chemistry; Oxford University Press: Oxford, 2013.10.1093/acprof:oso/9780199669950.001.0001Search in Google Scholar

22. Spek, A. L. Acta Crystallogr. 2009, D65, 148–155; https://doi.org/10.1107/s090744490804362x.Search in Google Scholar

23. Brown, I. D. The Chemical Bond in Inorganic Chemistry: The Bond Valence Model; Oxford University Press: Oxford, UK, 2002.Search in Google Scholar

24. Lloyd, M. A., Brock, C. P. Acta Crystallogr. 1997, B53, 773–779; https://doi.org/10.1107/s0108768197005077.Search in Google Scholar

25. Klobasa, D. G., Burkert, P. K., Müller, G. Private Communication (Refcode SOVYIL, Deposition No. 1262728); CCDC: Cambridge, UK, 1992.Search in Google Scholar

26. Bohrer, R., Conradi, E., Müller, U. Z. Anorg. Allg. Chem. 1988, 558, 119–127; https://doi.org/10.1002/zaac.19885580111.Search in Google Scholar

27. Deringer, V. L., Wang, A., George, J., Dronskowski, R., Englert, U. Dalton Trans. 2016, 45, 13680–13685; https://doi.org/10.1039/c6dt02487d.Search in Google Scholar PubMed

28. Bernardinelli, G., Lucken, E. A. C., Costines, M. Z. Kristallogr. 1991, 195, 141–142; https://doi.org/10.1524/zkri.1991.195.1-2.141.Search in Google Scholar

29. Hook, J. M., Dean, P. A. W., Hockless, D. C. R. Acta Crystallogr. 1995, C51, 1547–1549; https://doi.org/10.1107/s010827019500196x.Search in Google Scholar

30. Persson, I., Eriksson, L., Lindqvist-Reis, P., Persson, P., Sandström, M. Chem. Eur. J. 2008, 14, 6687–6696; https://doi.org/10.1002/chem.200800225.Search in Google Scholar PubMed

31. Robinson, K., Gibbs, G. V., Ribbe, P. H. Science 1971, 172, 567–570; https://doi.org/10.1126/science.172.3983.567.Search in Google Scholar PubMed

32. Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordination Compounds: Part B: Applications in Coordination, Organometallic, and Bioinorganic Chemistry, 6th ed.; John Wiley & Sons, Inc: Hoboken, NJ, 2008.10.1002/9780470405888Search in Google Scholar

33. Pearson, R. G. J. Chem. Educ. 1968, 45, 581–587; https://doi.org/10.1021/ed045p581.Search in Google Scholar

34. Shannon, R. D. Acta Crystallogr. 1976, A32, 751–767; https://doi.org/10.1107/s0567739476001551.Search in Google Scholar

35. Saint+ (version 7.68), Program for Reduction of Data Collected on Bruker CCD Area Detector Diffractometer; Bruker AXS Inc.: Madison,  Wisconson, USA, 2009.Search in Google Scholar

36. Sheldrick, G. M. Sadabs, A Program for Empirical Absorption Correction of Area Detector Data; University of Göttingen: Göttingen, Germany, 2014.Search in Google Scholar

37. Stoe & Cie. X-Area; Stoe & Cie GmbH: Darmstadt, Germany, 2017.Search in Google Scholar

38. Koziskova, J., Hahn, F., Richter, J., Kozısek, J. Acta Chim. Slov. 2016, 9, 136–140.10.1515/acs-2016-0023Search in Google Scholar

39. Sheldrick, G. M. Acta Crystallogr. Sect. A 2015, 71, 3–8; https://doi.org/10.1107/s2053229614024218.Search in Google Scholar

40. Sheldrick, G. M. Acta Crystallogr. Sect. C 2015, 71, 3–8.10.1107/S2053229614024218Search in Google Scholar

41. Aurivillius, K., Carlsson, I.-B. Acta Chem. Scand. 1957, 11, 1069; https://doi.org/10.3891/acta.chem.scand.11-1069.Search in Google Scholar

42. Aurivillius, K. Acta Chem. Scand. 1964, 18, 1305–1306; https://doi.org/10.3891/acta.chem.scand.18-1305.Search in Google Scholar

Supplementary Material

The online version of this article offers supplementary material (https://doi.org/10.1515/znb-2021-0101).

Received: 2021-07-28
Accepted: 2021-08-20
Published Online: 2021-09-20
Published in Print: 2021-11-25

© 2021 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  2. In this issue
  3. Laudatio/Preface
  4. Celebrating the 60th birthday of Richard Dronskowski
  5. Review
  6. Orbital-selective electronic excitation in phase-change memory materials: a brief review
  7. Research Articles
  8. Solving the puzzle of the dielectric nature of tantalum oxynitride perovskites
  9. d- and s-orbital populations in the d block: unbound atoms in physical vacuum versus chemical elements in condensed matter. A Dronskowski-population analysis
  10. Single-crystal structures of A 2SiF6 (A = Tl, Rb, Cs), a better structure model for Tl3[SiF6]F, and its novel tetragonal polymorph
  11. Na2La4(NH2)14·NH3, a lanthanum-rich intermediate in the ammonothermal synthesis of LaN and the effect of ammonia loss on the crystal structure
  12. Linarite from Cap Garonne
  13. Salts of octabismuth(2+) polycations crystallized from Lewis-acidic ionic liquids
  14. High-temperature diffraction experiments and phase diagram of ZrO2 and ZrSiO4
  15. Thermal conversion of the hydrous aluminosilicate LiAlSiO3(OH)2 into γ-eucryptite
  16. Crystal structure of mechanochemically prepared Ag2FeGeS4
  17. Effect of nanostructured Al2O3 on poly(ethylene oxide)-based solid polymer electrolytes
  18. Sr7N2Sn3: a layered antiperovskite-type nitride stannide containing zigzag chains of Sn4 polyanions
  19. Exploring the frontier between polar intermetallics and Zintl phases for the examples of the prolific ALnTnTe3-type alkali metal (A) lanthanide (Ln) late transition metal (Tn) tellurides
  20. Zwitterion coordination to configurationally flexible d 10 cations: synthesis and characterization of tetrakis(betaine) complexes of divalent Zn, Cd, and Hg
  21. An approach towards the synthesis of lithium and beryllium diphenylphosphinites
  22. Synthesis, crystal and electronic structure of CaNi2Al8
  23. Crystal and electronic structure of the new ternary phosphide Ho5Pd19P12
  24. Synthesis, structure, and magnetic properties of the quaternary oxysulfides Ln 5V3O7S6 (Ln = La, Ce)
  25. Synthesis, crystal and electronic structure of BaLi2Cd2Ge2
  26. Structural variations of trinitrato(terpyridine)lanthanoid complexes
  27. Preparation of CoGe2-type NiSn2 at 10 GPa
  28. Controlled exposure of CuO thin films through corrosion-protecting, ALD-deposited TiO2 overlayers
  29. Experimental and computational investigations of TiIrB: a new ternary boride with Ti1+x Rh2−x+y Ir3−y B3-type structure
  30. Synthesis and crystal structure of the lanthanum cyanurate complex La[H2N3C3O3]3 · 8.5 H2O
  31. Cd additive effect on self-flux growth of Cs-intercalated NbS2 superconducting single crystals
  32. 14N, 13C, and 119Sn solid-state NMR characterization of tin(II) carbodiimide Sn(NCN)
  33. Superexchange interactions in AgMF4 (M = Co, Ni, Cu) polymorphs
  34. Copper(I) iodide-based organic–inorganic hybrid compounds as phosphor materials
  35. On iodido bismuthates, bismuth complexes and polyiodides with bismuth in the system BiI3/18-crown-6/I2
  36. Synthesis, crystal structure and selected properties of K2[Ni(dien)2]{[Ni(dien)]2Ta6O19}·11 H2O
  37. First low-spin carbodiimide, Fe2(NCN)3, predicted from first-principles investigations
  38. A novel ternary bismuthide, NaMgBi: crystal and electronic structure and electrical properties
  39. Magnetic properties of 1D spin systems with compositional disorder of three-spin structural units
  40. Amine-based synthesis of Fe3C nanomaterials: mechanism and impact of synthetic conditions
  41. Enhanced phosphorescence of Pd(II) and Pt(II) complexes adsorbed onto Laponite for optical sensing of triplet molecular dioxygen in water
  42. Theoretical investigations of hydrogen absorption in the A15 intermetallics Ti3Sb and Ti3Ir
  43. Assembly of cobalt-p-sulfonatothiacalix[4]arene frameworks with phosphate, phosphite and phenylphosphonate ligands
  44. Chiral bis(pyrazolyl)methane copper(I) complexes and their application in nitrene transfer reactions
  45. UoC-6: a first MOF based on a perfluorinated trimesate ligand
  46. PbCN2 – an elucidation of its modifications and morphologies
  47. Flux synthesis, crystal structure and electronic properties of the layered rare earth metal boride silicide Er3Si5–x B. An example of a boron/silicon-ordered structure derived from the AlB2 structure type
https://doi.org/10.1515/znb-2021-0101
Keywords for this article
betaine coordination; d 10 complexes; pseudosymmetry

Articles in the same Issue

  1. Frontmatter
  2. In this issue
  3. Laudatio/Preface
  4. Celebrating the 60th birthday of Richard Dronskowski
  5. Review
  6. Orbital-selective electronic excitation in phase-change memory materials: a brief review
  7. Research Articles
  8. Solving the puzzle of the dielectric nature of tantalum oxynitride perovskites
  9. d- and s-orbital populations in the d block: unbound atoms in physical vacuum versus chemical elements in condensed matter. A Dronskowski-population analysis
  10. Single-crystal structures of A 2SiF6 (A = Tl, Rb, Cs), a better structure model for Tl3[SiF6]F, and its novel tetragonal polymorph
  11. Na2La4(NH2)14·NH3, a lanthanum-rich intermediate in the ammonothermal synthesis of LaN and the effect of ammonia loss on the crystal structure
  12. Linarite from Cap Garonne
  13. Salts of octabismuth(2+) polycations crystallized from Lewis-acidic ionic liquids
  14. High-temperature diffraction experiments and phase diagram of ZrO2 and ZrSiO4
  15. Thermal conversion of the hydrous aluminosilicate LiAlSiO3(OH)2 into γ-eucryptite
  16. Crystal structure of mechanochemically prepared Ag2FeGeS4
  17. Effect of nanostructured Al2O3 on poly(ethylene oxide)-based solid polymer electrolytes
  18. Sr7N2Sn3: a layered antiperovskite-type nitride stannide containing zigzag chains of Sn4 polyanions
  19. Exploring the frontier between polar intermetallics and Zintl phases for the examples of the prolific ALnTnTe3-type alkali metal (A) lanthanide (Ln) late transition metal (Tn) tellurides
  20. Zwitterion coordination to configurationally flexible d 10 cations: synthesis and characterization of tetrakis(betaine) complexes of divalent Zn, Cd, and Hg
  21. An approach towards the synthesis of lithium and beryllium diphenylphosphinites
  22. Synthesis, crystal and electronic structure of CaNi2Al8
  23. Crystal and electronic structure of the new ternary phosphide Ho5Pd19P12
  24. Synthesis, structure, and magnetic properties of the quaternary oxysulfides Ln 5V3O7S6 (Ln = La, Ce)
  25. Synthesis, crystal and electronic structure of BaLi2Cd2Ge2
  26. Structural variations of trinitrato(terpyridine)lanthanoid complexes
  27. Preparation of CoGe2-type NiSn2 at 10 GPa
  28. Controlled exposure of CuO thin films through corrosion-protecting, ALD-deposited TiO2 overlayers
  29. Experimental and computational investigations of TiIrB: a new ternary boride with Ti1+x Rh2−x+y Ir3−y B3-type structure
  30. Synthesis and crystal structure of the lanthanum cyanurate complex La[H2N3C3O3]3 · 8.5 H2O
  31. Cd additive effect on self-flux growth of Cs-intercalated NbS2 superconducting single crystals
  32. 14N, 13C, and 119Sn solid-state NMR characterization of tin(II) carbodiimide Sn(NCN)
  33. Superexchange interactions in AgMF4 (M = Co, Ni, Cu) polymorphs
  34. Copper(I) iodide-based organic–inorganic hybrid compounds as phosphor materials
  35. On iodido bismuthates, bismuth complexes and polyiodides with bismuth in the system BiI3/18-crown-6/I2
  36. Synthesis, crystal structure and selected properties of K2[Ni(dien)2]{[Ni(dien)]2Ta6O19}·11 H2O
  37. First low-spin carbodiimide, Fe2(NCN)3, predicted from first-principles investigations
  38. A novel ternary bismuthide, NaMgBi: crystal and electronic structure and electrical properties
  39. Magnetic properties of 1D spin systems with compositional disorder of three-spin structural units
  40. Amine-based synthesis of Fe3C nanomaterials: mechanism and impact of synthetic conditions
  41. Enhanced phosphorescence of Pd(II) and Pt(II) complexes adsorbed onto Laponite for optical sensing of triplet molecular dioxygen in water
  42. Theoretical investigations of hydrogen absorption in the A15 intermetallics Ti3Sb and Ti3Ir
  43. Assembly of cobalt-p-sulfonatothiacalix[4]arene frameworks with phosphate, phosphite and phenylphosphonate ligands
  44. Chiral bis(pyrazolyl)methane copper(I) complexes and their application in nitrene transfer reactions
  45. UoC-6: a first MOF based on a perfluorinated trimesate ligand
  46. PbCN2 – an elucidation of its modifications and morphologies
  47. Flux synthesis, crystal structure and electronic properties of the layered rare earth metal boride silicide Er3Si5–x B. An example of a boron/silicon-ordered structure derived from the AlB2 structure type
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 10.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/znb-2021-0101/html
Scroll to top button