Startseite The novel [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}I2] complex: Structural features and catalytic reactivity in the oligomerization of ethylene
Artikel Open Access

The novel [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}I2] complex: Structural features and catalytic reactivity in the oligomerization of ethylene

  • Ioannis Stamatopoulos , Catherine P. Raptopoulou , Vassilis Psycharis und Panayotis Kyritsis EMAIL logo
Veröffentlicht/Copyright: 30. Dezember 2016
Artikel downloaden (PDF)
Open Chemistry
Aus der Zeitschrift Open Chemistry Band 14 Heft 1

Abstract

The novel [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}I2] complex (1) was synthesized and investigated by a variety of spectroscopic methods (IR, 1H and 31P NMR). The molecular structure of 1, determined by single crystal X-ray diffraction, was compared with those of the analogue [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}Cl2] complex (2) and the recently reported [Ni{iCPrP)2NH-P,P´}I2] complex. Complexes 1 and 2 were tested as homogeneous catalysts for the oligomerization of ethylene, leading to the formation of C4 and, to a smaller extent, C6 products, in moderate yields.

Keywords: nickel; bis(phosphino)amine; ethylene oligomerization; homogeneous catalysis

1 Introduction

The preparation of linear olefins (up to C10) is a field of significant interest, as these compounds are widely used in the chemical industry, for instance in the fabrication of various value-added chemical products by co-polymerization with ethylene [1]. Ethylene oligomerization affords a variety of up to C10 olefins, with 1-olefins being the most desirable ones [2]. A variety of metal complexes bearing various ligands have been extensively studied as catalysts for the oligomerization of ethylene, with chromium [2] and nickel [3] complexes being among the most common ones. Among various types of ligands employed for the synthesis of such catalysts, bis(phosphino)amines, (R2P)2N(R′), in the following referred to as (P,P), have been shown to afford a host of coordination compounds [4], the catalytic reactivity of which is under extensive investigation [5]. Among them, a large number of Cr(0) complexes bearing different N-substituent R′ groups have been shown to be rather active catalysts for these reactions [6-10]. The nature of the R and R′ group modifies the stereochemical and electronic properties of these catalysts, thus affecting their catalytic reactivity well [2]. On the other hand, complexes of Ni(II) bearing bis(phosphino) amine ligands have not been investigated as extensively. Up to now, complexes of the [Ni(P,P)X2], X = Cl, Br, general type, have been shown to catalyze the polymerization of ethylene [11] or norbornene [12, 13], as well as the oligomerization of ethylene [14-16].

With respect to the catalytic reactivity of such Ni(II) complexes in the oligomerization of ethylene, the reported studies have primarily probed the effects of i) the nature of the R′ and R groups, ii) the size of the metal-ligand chelate ring by employing either (P,P) or (P,P=S) ligands [14-16]. These literature complexes contain either X = Cl or Br and, to the best of our knowledge, no [Ni(P,P)I2] complexes have been investigated. For that reason, in the work presented herein, the synthesis and characterization of a Ni(II) complex of this type, namely [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P′}I2] (1), is described. This compound bears the Si(OCH3)3 group, via which it can be immobilized onto solid supports, as it has recently been shown for the structurally characterized analogous X = Cl (2) compound, which is an active heterogenized catalyst for the Kumada C−C coupling reaction [17, 18]. In an effort to probe the effects of the nature of the Ni(II)-coordinated halides X = Cl, I, the structural and spectroscopic properties of complex 1 was determined by X-ray crystallography and IR/NMR spectroscopies and compared with those of complex 2[17]. In addition, complexes 1 and 2 were investigated as homogeneous catalysts for the oligomerization of ethylene.

2 Experimental

2.1 Synthesis

All synthetic experiments were carried out using standard Schlenk and vacuum line techniques, under an argon atmosphere. The solvents employed were dried and distilled according to published procedures [19]. The chemical reagents (3-aminopropyl)trimethoxy silane (97%) and chlorodiphenylphosphine (97%) were purchased from Alfa Aesar, whereas triethylamine (99%) from Merck. The bis(phosphino)amine ligand (Ph2P)2N(CH2)3Si(OCH3)3[20] and complex 2[17] were prepared according to published procedures.

Synthesis of complex 1. An amount of NaI (222 mg, 1.480 mmol) was added to an acetone solution of complex 2 (100 mg, 0.148 mmol) under argon. After the addition of NaI, the color of the solution changed from orange to purple. The reaction mixture was then stirred at room temperature for 2 h. The solvent was removed under vacuum and CH2Cl2 (10 mL) was added. The solution was filtered in order to separate the solution from the insoluble salts, and n-hexane (20 mL) was added to the filtrate, leading to the formation of a purple solid. The purple solid was collected by filtration and dried under vacuum. Yield: 112 mg, 88%. IR peaks (cm−1): 2932, 2829, 1475, 1430, 1304, 1259, 1183, 1135, 1095, 1023, 997, 862, 827, 747, 718, 694, 558, 511. 1H NMR (300 MHz, CDCl3, ppm): 0.10 (2 H, Si-CH2), 1.10 (2 H, -CH2-), 2.67 (2 H, N-CH2), 3.31 (9 H, Si-OCH3), 75-8.0 (20 H, aromatics). 31P{1H} NMR (121.4 MHz, CDCl3, ppm): 61.6.

2.2 IR and NMR spectroscopy

FT-IR spectra were recorded in an IRAffinity-1 SHIMANDZU instrument using KBr pellets. 1H-NMR spectra were recorded in a Varian 300 MHz instrument, at room temperature, in a CDCl3 solution. A solution of H3PO4(aq) (85% w/w) was used as an external standard for the 31P{1H} NMR spectra.

2.3 X-ray crystallography

The crystallographic data for compound 1 is listed in Table 1. A crystal of 1 (0.3× 0.4× 0.6 mm) was taken from the mother liquor and immediately cooled to -113 °C. Diffraction measurements were made on a Rigaku R-AXIS SPIDER Image Plate diffractometer, using graphite monochromated Cu Kα radiation. Data collection (ω-scans) and processing (cell refinement, data reduction and numerical absorption correction) were performed using the CrystalClear program package [21]. The structure was solved by direct methods using SHELXS-97 [22] and refined by full-matrix least-squares methods on F2 with SHELXL2014/6 [23].

Table 1

Crystallographic data of complex 1.

FormulaC30H35I2NO3P2NiSi
Fw860.13
T (K)160
radiationCu Kα
Crystal systemOrthorhombic
Space groupPmcn
a (Å)18.0618 (1)
b (Å)8.7983 (1)
c (Å)21.7705 (1)
Volume (Å3)3459.62 (5)
Z4
D(calc), Mg m−31.651
Abs. coef., μ, mm−116.27
GOF on F21.05
Measured/ unique/18390/2992/
reflections with I>2σ(I)2808
Rint0.099
R1 / wR2 (total)0.0398/0.1020
R1 / wR2 [for I>2σ(I)]0.0382/0.1005
CCDC deposition code1517231

R1 = ∑(|F0|−|Fc|)/∑(|F0|) and wR2 = {∑[w(F02−Fc2)2]/∑[w(F02)2]}1/2w = 1/[σ2(F02)+(αP)2+bP] and P = [F02+2Fc2]/3, α = 0.0361, b = 5.4158

Further experimental crystallographic details: 2θmax = 130.00 °; 251 parameters refined; (Δ/σ)max = 0.001; (Δρ)max/(Δρ)min = 1.09/-1.26 e/Å3. Two of the methyl groups of the ligand in structure 1 are in disordered positions and were refined with PART -1 instruction, considering 0.5 occupancies for both positions. The hydrogen atoms were refined isotropically at positions located either from difference Fourier Maps or at calculated ones using a riding model. All non-hydrogen atoms for both complexes were refined anisotropically.

2.4 Ethylene oligomerization

In a typical procedure, 10 μmol of the catalyst (complex 1 or 2) were transferred in a Young’s tube and 20 mL of toluene were added. After stirring for 15 min, methylaluminoxane (MAO) (300 equivalents, 2.0 mL of 10% w/w solution in toluene) was added to the mixture. The flask was placed under vacuum for a short time and then it was filled with ethylene until the pressure reached 1 bar. The mixture was stirred for 1 h at 1 bar ethylene pressure, then cooled at 0 °C and the reaction was quenched by the addition of 5 mL of HCl(aq) 10%. Mesitylene (0.25 mL) was added as internal standard. The flask was then cooled to -20 °C and an aliquote was taken from the organic layer, filtered and analyzed by gas chromatography (GC). Experiments employing higher ethylene pressure (10 bar) were performed in an autoclave reactor, under the experimental conditions described above. Ethylene oligomerization products were detected by GC-FID using a Varian L3800, fitted with a Varian WC07 fused silica capillary column, 25 m × 0.25 mm, i.d. coating CP-Sil 5CB, DF = 0.25. Ethylene oligomerization method: 40 to 80 °C at 2 °C min−1, then 80 to 250 °C at 10 °C min−1.

3 Results and Discussion

3.1 Synthesis and spectroscopic characterization of complex 1

Complex 1 was prepared by adding an excess of NaI to an acetone solution of 2[17], leading to the substitution of Cl− by I− (Scheme 1).

Scheme 1 Synthesis of complex 1.
Scheme 1

Synthesis of complex 1.

Complex 1 exhibits a very small 31P NMR chemical shift difference compared with the (Ph2P)2N(CH2)3Si(OCH3)3 ligand (61.6 versus 62.2 ppm [17], respectively). It should be noted that this difference is significantly larger for complex 2, which exhibits the corresponding peak at 42.8 ppm [17]. These observations would merit additional investigations. The synthesis and characterization of the [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}Br2] analogue, which is currently underway, will shed more light on this matter. The appearance of only one 31P NMR peak for complex 1 signifies that, at room temperature, its two P atoms are magnetically equivalent. This is also confirmed by the crystal structure of complex 1, which exhibits a mirror plane (Fig. 1), as detailed in the following.

Figure 1 Molecular structure and atom numbering of complex 1 (ORTER diagram, 50% thermal ellipsoids). The hydrogen atoms are omitted for clarity. The atoms at the disordered sites are shown in gray. Symmetry code: (′): -0.5-x,y,z. The structure has a mirror plane of symmetry, passing through the atoms: Ni, N, C21, C22, C23, Si, 021 and C24.
Figure 1

Molecular structure and atom numbering of complex 1 (ORTER diagram, 50% thermal ellipsoids). The hydrogen atoms are omitted for clarity. The atoms at the disordered sites are shown in gray. Symmetry code: (′): -0.5-x,y,z. The structure has a mirror plane of symmetry, passing through the atoms: Ni, N, C21, C22, C23, Si, 021 and C24.

3.2 Structural features of complex 1

Single crystals of complex 1 suitable for X-ray diffraction studies were obtained by the slow diffusion of n-hexane into a CH2Cl2 solution of complex 1 (layering method, CH2Cl2/n-hexane 1:3 v/v). The main crystallographic and structural data are listed in Tables 1 and 2, respectively.

Table 2

Selected bond lengths and angles of complexes 1, 2 and 3.

ComplexXR’ groupbond lengths (Å)
Ni−P1Ni−P2Ni−X1Ni−X2N−P1N−P2N−X
1I(CH2)3Si(OCH3)32.1382.1382.5012.5011.6901.6901.493
2[17]Cl(CH2)3Si(OCH3)32.1252.1312.1962.1881.6931.6901.475
3[25]IH2.1462.1442.5402.5201.6881.6810.801
Complexbond angles (°)
X1-Ni-X2X1-Ni-P1X2-Ni-P2P1-Ni-P2Ni-P1-NNi-P2-NP1-N-P2
197.6594.3894.3873.5993.8493.8498.56
297.6294.1295.0673.3994.6294.5197.46
399.7594.3894.2973.1693.4993.7698.73

The structure of complex 1 (Fig. 1) contains discrete molecules containing a NiP2I2 first coordination sphere of distorted square planar geometry. The metal center is coordinated by the (P,P) chelate, maintaining a four-member Ni-P-N-P ring of complex 2 used for its synthesis (Scheme 1). The NiP2I2 core is almost planar, showing a small (0.007 Å) mean deviation from the best plane defined by the Ni, P and I atoms, with the I atom exhibiting the largest deviation (0.011 Å). Moreover, the four-member Ni-P-N-P ring is essential planar, with the mean deviation from the best plane defined by these four atoms being 0.0262(5) Å.

A search in the Cambridge Structural Database (CSD) [24] for deposited structures of [Ni(P,P)I2] complexes, showed none. However, the structure of [Ni{(iPr2P)2NH- P,P´}I2] (3) has been very recently reported in the literature. [25] The main bond lengths and angles of the later, along with those of complexes 1 and 2[17], are listed in Table 2. It should be noted that the structure of one [Pd(P,P)I2] complex (bearing one Me and three Ph as R groups and R′ = iPr) [26] and two [Pt(P,P)I2] complexes (R = Ph, R′ = C6H4(CO2CH3)[27] or Ph [28]), have been reported and are available in the CSD.

By inspecting the structure of complex 1, the intermolecular interactions of the C−H ••• π type are evident, involving the ligands’ CH3 and Ph groups of neighboring molecules. A structural disorder involving two of the three –OCH3 groups is observed in complex 1, and it has also been observed for complex 2[17]. More significantly, complex 1 exhibits a mirror plane of symmetry (Fig. 1), unlike complex 2. The bond lengths in the two complexes exhibit certain differences, located mostly in the NiP2X2, X = Cl, I, coordination sphere. As expected, the Ni−I bond length is larger than the Ni−Cl one [2.501 and 2.192 Å (average), respectively]. In addition, the Ni−P bond lengths in complex 2 (average 2.128 Å) are slightly shorter compared with those of 1 (2.138 Å).

In comparing the structural features of complexes 1 and 3[25], it is of interest to note that the atoms of the NiP2I2 core in complex 3 are not located in the same plane.

More specifically, the mean deviation from the best plane defined by the Ni, P, I atoms is 0.1458 Å, with the P atom showing the largest deviation (0.458 Å). The Ni−I and Ni−P bond lengths of complex 3 are slightly larger and shorter, respectively, than those of complex 1.

A comparison of the bond angles of complexes 1, 2 and 3, show a larger I-Ni-I value in complex 3, and the X = I complexes 1 and 3 exhibit slightly larger P-N-P angles compared with that of complex 2. The three complexes exhibit similar P-Ni-P angles (Table 2), the magnitude of which seems to be controlled by the formation of the four-member Ni-P-N-P ring.

3.3 Ethylene oligomerization

Complexes 1 and 2 were tested as catalysts for the oligomerization of ethylene (Table 3). The experiments were carried out in the presence of methylaluminoxane (MAO), under an ethylene pressure of either 1 or 10 bar. The reactions lead, in moderate yields, to primarily C4 products (dimerization of ethylene) and only small amounts of the C6 oligomers (Table 3). At low ethylene pressure (1 bar), complex 1 exhibits a larger selectivity for 1-C6 products compared with that of complex 2, whereas at 10 bar the two complexes exhibit similar selectivity. It should be stressed that due to the moderate activity of complexes 1 and 2, there are significant differences in the data obtained from experiments performed under the same conditions (entries a and b, Table 3). The observed differences between the catalytic activity of complexes 1 and 2 may be explained by their main structural difference, namely the large difference in their Ni−X bond length, X = I, Cl, (2.501 and 2.196 Å, respectively, Table 2). This difference, may lead to diverse ways of substrate coordination and activation in the first coordination sphere of the catalyst. Ongoing investigations on the catalytic activity and sensitivity of the X = Br analogue, under similar experimental conditions, are expected to shed more light concerning this matter.

Table 3

Catalytic ethylene oligomerization by complexes 1 and 2.

Complex12
Activitya145388
g (gcat h)−1b220350
c600800
C4 %a8791
b8592
c9290
C6 %a139
b136
c810
1-C6 %a575
b2310
c2530

All percentages are by mass. The fraction 1-C6 is given as a percentage of the C6 total fraction. Experiments a and b were performed under low ethylene pressure (1 bar), whereas experiments c under 10 bar of ethylene pressure.

The ethylene pressure affects the catalytic activity. Catalytic reactions performed at a higher ethylene pressure (10 bar), provided higher yields and improved catalytic activities. Increased pressure increases the yield in C4 products, but the selectivity in C6 products remains moderate (Table 3). The relatively low selectivity of both complexes in producing 1-C6, at 10 bar of ethylene pressure, is compatible with a co-dimerization process of the C4 products and unreacted ethylene, leading to branched C6 products, as previously suggested in the literature [15].

4 Conclusions

The novel [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}I2] complex (1) was synthesized and structurally characterized by X-ray crystallography. The structural features of this compound were compared with those of the recently reported complexes [Ni{(iPrP)2NH-P,P´}I2] (3) and [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}Cl2] (2). Complexes 1 and 2 were tested as homogeneous catalysts for the oligomerization of ethylene, leading to the formation of C4 and, to a smaller extent, C6 products, both in moderate yield. The catalytic reactivity of immobilized complexes 1 and 2, as well as that of the [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}Br2] analogue complex, is currently under investigation and will be reported at a later date.

Acknowledgements

I.S. and P.K. would like to thank Professor Duncan Wass and Dr Helen Coulshed (School of Chemistry, University of Bristol) for assistance with the catalytic testing and helpful discussions. The authors acknowledge the “IKY Fellowships of excellence for postgraduate studies in Greece – Siemens Program” for financial support. P.K. participated in the activities of the CM0802 Cost Action (PhoSciNet) and thanks the PhoSciNet members Prof. E. Hey-Hawkins, Prof. M. Peruzzini and Dr. I.D. Kostas for helpful discussions.

References

[1] Lappin G.R., Nemec L.H., Sauer J.D., Wagner J.D., Higher Olefins. Kirk-Othmer Encyclopedia of Chemical Technlogy, Wiley & Sons, Inc., 2005.Suche in Google Scholar

[2] Agapie T., Selective ethylene oligomerization: Recent advances in chromium catalysis and mechanistic investigations, Coord. Chem. Rev., 2011, 255, 861-880.10.1016/j.ccr.2010.11.035Suche in Google Scholar

[3] Wang S., Sun W.-H., Redshaw C., Recent progress on nickelbased systems for ethylene oligo-polymerization catalysis, J, Organomet, Chem., 2014, 751, 717-741.10.1016/j.jorganchem.2013.08.021Suche in Google Scholar

[4] Appleby T., Woollins J.D., Inorganic backbone phosphines, Coord. Chem. Rev., 2002, 235, 121-140.10.1016/S0010-8545(02)00182-0Suche in Google Scholar

[5] Fliedel C., Ghisolfi A., Braunstein P., Functional short-bite ligands: Synthesis, coordination chemistry, and applications of N-functionalized bis(diaryl/dialkylphosphino)amine-type ligands, Chem. Rev., 2016, 116, 9237-9304.10.1021/acs.chemrev.6b00153Suche in Google Scholar PubMed

[6] Killian E., Blann K., Bollmann A., Dixon J.T., Kuhlmann S., Maumela M.C., Maumela H., Morgan D.H., Nongodlwana P., Overett M.J., Pretorius M., Hofener K., Wasserscheid P., The use of bis(diphenylphosphino)amines with N-aryl functionalities in selective ethylene tri- and tetramerisation, J. Mol. Catal. A: Chem., 2007, 270, 214-218.10.1016/j.molcata.2007.01.046Suche in Google Scholar

[7] Bowen L.E., Charernsuk M., Hey T.W., McMullin C.L., Orpen A.G., Wass D.F., Ligand effects in chromium diphosphine catalysed olefin co-trimerisation and diene trimerisation, Dalton Trans., 20l0, 39, 560-567.10.1039/B913302JSuche in Google Scholar PubMed

[8] Do L.H., Labinger J.A., Bercaw J.E., Spectral studies of a Cr(PNP)-MAO system for selective ethylene trimerization catalysis: Searching for the active species, ACS Catal., 2013, 3, 2582-2585.10.1021/cs400778aSuche in Google Scholar PubMed PubMed Central

[9] Britovsek G.J.P., McGuinness D.S., Wierenga T.S., Young C.T., Single- and double-coordination mechanism in ethylene tri- and tetramerization with Cr/PNP catalysts, ACS Catal., 2015, 5, 4152-4166.10.1021/acscatal.5b00989Suche in Google Scholar

[10] Sa S., Lee S.M., Kim S.Y., Chromium-based ethylene tetramerization with diphosphinoamines bearing pendent amine donors, J. Mol. Catal. A: Chem., 2013, 378, 17-21.10.1016/j.molcata.2013.05.015Suche in Google Scholar

[11] Cooley N.A., Green S.M., Wass D.F., Heslop K., Orpen A.G., Pringle P.G., Nickel ethylene polymerization catalysts based on phosphorus ligands, Organometallics, 200l, 20, 4769-4771.10.1021/om010705pSuche in Google Scholar

[12] Sun Z.G., Zhu F.M., Wu Q., Lin S.A., Vinyl polymerization of norbornene with novel nickel(II) diphosphinoamine/ methylaluminoxane catalytic system, Appl. Organomet. Chem., 2006, 20, 175-180.10.1002/aoc.1024Suche in Google Scholar

[13] Vougioukalakis G.C., Stamatopoulos I., Petzetakis N., Raptopoulou C.P., Psycharis V., Terzis A., Kyritsis P., Pitsikalis M., Hadjichristidis N., Controlled vinyl-type polymerization of norbornene with a nickel(II) diphosphinoamine/ methylaluminoxane catalytic system, J. Polym. Sci. A Polym. Chem., 2009, 47, 5241-5250.10.1002/pola.23573Suche in Google Scholar

[14] Song K.M., Gao H.Y., Liu F.S., Pan J., Guo L.H., Zai S.B., WU Q., Syntheses, structures, and catalytic ethylene oligomerization behaviors of bis(phosphanyl)aminenickel(II) complexes containing N-functionalized pendant groups, Eur. J. Inorg. Chem., 2009, 20, 3016-3024.10.1002/ejic.200900256Suche in Google Scholar

[15] Boulens P., Lutz M., Jeanneau E., Olivier-Bourbigou H., Reek J.N.H., Breuil P.-A.R., lminobisphosphines to (non-)symmetrical diphosphinoamine ligands: Metal-induced synthesis of diphosphorus nickel complexes and application in ethylene oligomerization reactions, Eur. J. Inorg. Chem., 2014, 23, 3754-3762.10.1002/ejic.201402430Suche in Google Scholar

[16] Ghisolfi A., Fliedel C., Rosa V., Monakhov K.Y., Braunstein P., Combined experimental and theoretical study of bis(diphenylphosphino)(N-thioether)amine-type ligands in nickel(II) complexes for catalytic ethylene oligomerization, Organometallics, 2014, 33, 2523-2534.10.1021/om500141kSuche in Google Scholar

[17] Stamatopoulos I., Giannitsios D., Psycharis V., Raptopoulou C.P., Balcar H., Zukal A., Svoboda J., Kyritsis P., Vohlidal J., A Kumada coupling catalyst, [Ni{(Ph2P)2N(CH2)BSi(OCHB)B-P,P} Cl2], bearing a ligand for direct immobilization onto siliceous mesoporous molecular sieves, Eur. J. Inorg. Chem., 2015, 18, 3038-3044.10.1002/ejic.201500447Suche in Google Scholar

[18] Stamatopoulos I., Plaček M., Psycharis V., Terzis A., Svoboda J., Kyritsis P., Vohlídal J., Structural and spectroscopic characteristics of [Ni{(Ph2P)2N-S-CHMePh-P,P′}X2], X = Cl, Br: Catalytic activity and selectivity in Kumada and Suzuki–Miyaura coupling reactions, Inorg. Chim. Acta., 2012, 387, 390-395.10.1016/j.ica.2012.02.033Suche in Google Scholar

[19] Armarego W.L.F., Chai C.L.L., Purification of Laboratory Chemicals, Fith Edition, Butterworth-Heinemann, 2003.10.1016/B978-075067571-0/50008-9Suche in Google Scholar

[20] Braunstein P., Kormann H.-P., Meyer-Zaika W., Pugin R., Schmid G., Strategies for the anchoring of metal complexes, clusters, and colloids inside nanoporous alumina membranes, Chem. Eur. J., 2000, 6, 4637-4646.10.1002/1521-3765(20001215)6:24<4637::AID-CHEM4637>3.0.CO;2-ASuche in Google Scholar

[21] CrystalClear, Rigaku/MSC Inc., The Woodlands, TX, 2005.Suche in Google Scholar

[22] Sheldrick G., A short history of SHELX, Acta Cryst. A, 2008, 64, 112-122.10.1107/S0108767307043930Suche in Google Scholar

[23] Sheldrick G.M., Crystal structure refinement with SHELXL, Acta Cryst. C, Structural Chemistry, 2015, 71, 3-8.10.1107/S2053229614024218Suche in Google Scholar

[24] Allen F.H., The Cambridge Structural Database: a quarter of a million crystal structures and rising, Acta Cryst. B, 2002, 58, 380-388.10.1107/S0108768102003890Suche in Google Scholar

[25] Dickie D.A., Chacon B.E., lssabekov A., Lam K., Kemp R.A., Nickel(II) and nickel(0) complexes of bis(diisopropylphosphino) amine: Synthesis, structure, and electrochemical activity, Inorg. Chim. Acta., 2016, 453, 42-50.10.1016/j.ica.2016.07.048Suche in Google Scholar

[26] Kamalesh Babu R.P., Krishnamurthy S.S., Nethaji M., Organometallic chemistry of diphosphazanes—13.1 Palladium complexes of unsymmetrical diphosphazanes Ph2PN(Pri)PYY′, Polyhedron, 1996, 15, 2689-2699.10.1016/0277-5387(95)00561-7Suche in Google Scholar

[27] Gaw K.G., Smith M.B., Wright J.B., Slawin A.M.Z., Coles S.J., Hursthouse M.B., Tizzard G.J., Square-planar metal(II) complexes containing ester functionalised bis(phosphino)amines: Mild P-N methanolysis and carene-H cyclometallation, J. Organomet. Chem., 2012, 699, 39-47.10.1016/j.jorganchem.2011.11.003Suche in Google Scholar

[28] Punji B., Mague J.T., Balakrishna M.S., Highly air-stable anionic mononuclear and neutral binuclear palladium(II) complexes for C-C and C-N bond-forming reactions, Inorg. Chem., 2007, 46, 11316-11327.10.1021/ic701674xSuche in Google Scholar PubMed

Received: 2016-11-15
Accepted: 2016-12-8
Published Online: 2016-12-30
Published in Print: 2016-1-1

© 2016 Ioannis Stamatopoulos et al.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Artikel in diesem Heft

  1. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  2. Ion-exchange membranes in chemical synthesis – a review
  3. Regular Article
  4. Push-pull effect on the geometrical, optical and charge transfer properties of disubstituted derivatives of mer-tris(4-hydroxy-1,5-naphthyridinato) aluminum (mer-AlND3)
  5. Regular Article
  6. As, Cr, Cd, and Pb in Bee Products from a Polish Industrialized Region
  7. Regular Article
  8. Characteristic of wet method of phosphorus recovery from polish sewage sludge ash with nitric acid
  9. Regular Article
  10. Preparation and Characterization of Cerium (III) Doped Captopril Nanoparticles and Study of their Photoluminescence Properties
  11. Regular Article
  12. Silver nanoparticles – a material of the future…?
  13. Regular Article
  14. Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria
  15. Regular Article
  16. Potassium catalyzed hydrogasification of low-rank coal for synthetic natural gas production
  17. Regular Article
  18. The Radiochemical and Radiopharmaceutical Applications of Radium
  19. Regular Article
  20. Erratum to: the radiochemical and radiopharmaceutical applications of radium
  21. Regular Article
  22. Hydrothermal decomposition of actinide(IV) oxalates: a new aqueous route towards reactive actinide oxide nanocrystals
  23. Regular Article
  24. Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide
  25. Regular Article
  26. Erratum to: Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide
  27. Regular Article
  28. An extraction-chromogenic system for vanadium(IV,V) based on 2,3-dihydroxynaphtahlene
  29. Regular Article
  30. Commentary: Structure of spinach photosystem II–LHCII supercomplex at new high resolution
  31. Regular Article
  32. Analytical tools for determination of new oral antidiabetic drugs, glitazones, gliptins, gliflozins and glinides, in bulk materials, pharmaceuticals and biological samples
  33. Regular Article
  34. Development and validation of a new spectrofluorimetric method for the determination of some beta-blockers through fluorescence quenching of eosin Y. Application to content uniformity test
  35. Regular Article
  36. Modelling of acid-base titration curves of mineral assemblages
  37. Regular Article
  38. Preservation engineering assets developed from an oxidation predictive model
  39. Regular Article
  40. Flow microreactor synthesis of 2,2-disubstituted oxetanes via 2-phenyloxetan-2-yl lithium
  41. Regular Article
  42. Enhanced photocatalysts based on Ag-TiO2 and Ag-N-TiO2 nanoparticles for multifunctional leather surface coating
  43. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  44. Sorption of V and VI group metalloids (As, Sb, Te) on modified peat sorbents
  45. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  46. Adsorption of Cu (II) and Zn (II) from Water by Jatropha curcas L. as Biosorbent
  47. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  48. Erratum to: Adsorption of Cu (II) and Zn (II) from Water by Jatropha curcas L. as Biosorbent
  49. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  50. Hydrodynamic aspects of flotation separation
  51. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  52. Optimization of process parameters for heavy metals biosorption onto mustard waste biomass
  53. Topical Issue on Polymer Science
  54. Biomimetic superhydrophobic polyolefin surfaces fabricated with a facile scraping, bonding and peeling method
  55. Topical Issue on Polymer Science
  56. Poly(acrylamide)-MWNTs hybrid hydrogel with extremely high mechanical strength
  57. Topical Issue on Polymer Science
  58. Polyurethane modification with acrylic acid by Ce(IV)-initiated graft polymerization
  59. Topical Issue on Polymer Science
  60. Synthesis, Crystal Structure and Spectroscopic Analysis of a New Sodium Coordination Polymer
  61. Topical Issue on Polymer Science
  62. Preparation and characterization of cellulose paper/polypyrrole/bromophenol blue composites for disposable optical sensors
  63. Topical Issue on Advanced organic functional materials for practical applications
  64. ZnO nanoflowers-based photoanodes: aqueous chemical synthesis, microstructure and optical properties
  65. Topical Issue on Advanced organic functional materials for practical applications
  66. Bioactivities of Novel Metal Complexes Involving B Vitamins and Glycine
  67. Topical Issue on Catalysis
  68. Marine sponge skeleton photosensitized by copper phthalocyanine: A catalyst for Rhodamine B degradation
  69. Topical Issue on Catalysis
  70. Preparation and Application of a Nano α-Fe2O3/SAPO-34 Photocatalyst for Removal of the Anti-cancer Drug Doxorubicin using the Taguchi Approach
  71. Topical Issue on Catalysis
  72. Hydrogenolysis of glycerol over Pt/C catalyst in combination with alkali metal hydroxides
  73. Topical Issue on Catalysis
  74. A 2-(2’-pyridyl)quinoline ruthenium(II) complex as an active catalyst for the transfer hydrogenation of ketones
  75. Topical Issue on Catalysis
  76. Co-Rh modified natural zeolites as new catalytic materials to oxidize propane and naphthalene from emission sources
  77. Topical Issue on Catalysis
  78. The novel [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}I2] complex: Structural features and catalytic reactivity in the oligomerization of ethylene
  79. Topical Issue on Catalysis
  80. Ni-loaded nanocrystalline ceria-zirconia solid solutions prepared via modified Pechini route as stable to coking catalysts of CH4 dry reforming
  81. Topical Issue on Catalysis
  82. Photocatalytic Hydrogen Evolution by tris-dithiolene tungsten complexes
  83. Topical Issue on Natural Products with Biological Activities: Short Communication
  84. Microalgae-based unsaponifiable matter as source of natural antioxidants and metal chelators to enhance the value of wet Tetraselmis chuii biomass
  85. Topical Issue on Natural Products with Biological Activities
  86. Antioxidant and protease-inhibitory potential of extracts from grains of oat
  87. Topical Issue on Natural Products with Biological Activities
  88. Ammoides pusilla (Brot.) Breistr. from Algeria: Effect of harvesting place and plant part (leaves and flowers) on the essential oils chemical composition and antioxidant activity
https://doi.org/10.1515/chem-2016-0033
Schlagwörter für diesen Artikel
nickel; bis(phosphino)amine; ethylene oligomerization; homogeneous catalysis
Creative Commons
BY-NC-ND 3.0

Artikel in diesem Heft

  1. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  2. Ion-exchange membranes in chemical synthesis – a review
  3. Regular Article
  4. Push-pull effect on the geometrical, optical and charge transfer properties of disubstituted derivatives of mer-tris(4-hydroxy-1,5-naphthyridinato) aluminum (mer-AlND3)
  5. Regular Article
  6. As, Cr, Cd, and Pb in Bee Products from a Polish Industrialized Region
  7. Regular Article
  8. Characteristic of wet method of phosphorus recovery from polish sewage sludge ash with nitric acid
  9. Regular Article
  10. Preparation and Characterization of Cerium (III) Doped Captopril Nanoparticles and Study of their Photoluminescence Properties
  11. Regular Article
  12. Silver nanoparticles – a material of the future…?
  13. Regular Article
  14. Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria
  15. Regular Article
  16. Potassium catalyzed hydrogasification of low-rank coal for synthetic natural gas production
  17. Regular Article
  18. The Radiochemical and Radiopharmaceutical Applications of Radium
  19. Regular Article
  20. Erratum to: the radiochemical and radiopharmaceutical applications of radium
  21. Regular Article
  22. Hydrothermal decomposition of actinide(IV) oxalates: a new aqueous route towards reactive actinide oxide nanocrystals
  23. Regular Article
  24. Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide
  25. Regular Article
  26. Erratum to: Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide
  27. Regular Article
  28. An extraction-chromogenic system for vanadium(IV,V) based on 2,3-dihydroxynaphtahlene
  29. Regular Article
  30. Commentary: Structure of spinach photosystem II–LHCII supercomplex at new high resolution
  31. Regular Article
  32. Analytical tools for determination of new oral antidiabetic drugs, glitazones, gliptins, gliflozins and glinides, in bulk materials, pharmaceuticals and biological samples
  33. Regular Article
  34. Development and validation of a new spectrofluorimetric method for the determination of some beta-blockers through fluorescence quenching of eosin Y. Application to content uniformity test
  35. Regular Article
  36. Modelling of acid-base titration curves of mineral assemblages
  37. Regular Article
  38. Preservation engineering assets developed from an oxidation predictive model
  39. Regular Article
  40. Flow microreactor synthesis of 2,2-disubstituted oxetanes via 2-phenyloxetan-2-yl lithium
  41. Regular Article
  42. Enhanced photocatalysts based on Ag-TiO2 and Ag-N-TiO2 nanoparticles for multifunctional leather surface coating
  43. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  44. Sorption of V and VI group metalloids (As, Sb, Te) on modified peat sorbents
  45. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  46. Adsorption of Cu (II) and Zn (II) from Water by Jatropha curcas L. as Biosorbent
  47. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  48. Erratum to: Adsorption of Cu (II) and Zn (II) from Water by Jatropha curcas L. as Biosorbent
  49. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  50. Hydrodynamic aspects of flotation separation
  51. Special Issue on: Recycling by-products and waste materials to restore degraded environments, and/or use as biosorbents
  52. Optimization of process parameters for heavy metals biosorption onto mustard waste biomass
  53. Topical Issue on Polymer Science
  54. Biomimetic superhydrophobic polyolefin surfaces fabricated with a facile scraping, bonding and peeling method
  55. Topical Issue on Polymer Science
  56. Poly(acrylamide)-MWNTs hybrid hydrogel with extremely high mechanical strength
  57. Topical Issue on Polymer Science
  58. Polyurethane modification with acrylic acid by Ce(IV)-initiated graft polymerization
  59. Topical Issue on Polymer Science
  60. Synthesis, Crystal Structure and Spectroscopic Analysis of a New Sodium Coordination Polymer
  61. Topical Issue on Polymer Science
  62. Preparation and characterization of cellulose paper/polypyrrole/bromophenol blue composites for disposable optical sensors
  63. Topical Issue on Advanced organic functional materials for practical applications
  64. ZnO nanoflowers-based photoanodes: aqueous chemical synthesis, microstructure and optical properties
  65. Topical Issue on Advanced organic functional materials for practical applications
  66. Bioactivities of Novel Metal Complexes Involving B Vitamins and Glycine
  67. Topical Issue on Catalysis
  68. Marine sponge skeleton photosensitized by copper phthalocyanine: A catalyst for Rhodamine B degradation
  69. Topical Issue on Catalysis
  70. Preparation and Application of a Nano α-Fe2O3/SAPO-34 Photocatalyst for Removal of the Anti-cancer Drug Doxorubicin using the Taguchi Approach
  71. Topical Issue on Catalysis
  72. Hydrogenolysis of glycerol over Pt/C catalyst in combination with alkali metal hydroxides
  73. Topical Issue on Catalysis
  74. A 2-(2’-pyridyl)quinoline ruthenium(II) complex as an active catalyst for the transfer hydrogenation of ketones
  75. Topical Issue on Catalysis
  76. Co-Rh modified natural zeolites as new catalytic materials to oxidize propane and naphthalene from emission sources
  77. Topical Issue on Catalysis
  78. The novel [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P´}I2] complex: Structural features and catalytic reactivity in the oligomerization of ethylene
  79. Topical Issue on Catalysis
  80. Ni-loaded nanocrystalline ceria-zirconia solid solutions prepared via modified Pechini route as stable to coking catalysts of CH4 dry reforming
  81. Topical Issue on Catalysis
  82. Photocatalytic Hydrogen Evolution by tris-dithiolene tungsten complexes
  83. Topical Issue on Natural Products with Biological Activities: Short Communication
  84. Microalgae-based unsaponifiable matter as source of natural antioxidants and metal chelators to enhance the value of wet Tetraselmis chuii biomass
  85. Topical Issue on Natural Products with Biological Activities
  86. Antioxidant and protease-inhibitory potential of extracts from grains of oat
  87. Topical Issue on Natural Products with Biological Activities
  88. Ammoides pusilla (Brot.) Breistr. from Algeria: Effect of harvesting place and plant part (leaves and flowers) on the essential oils chemical composition and antioxidant activity
Jetzt anmelden und 20% sparen
Institutioneller Zugang
Wie funktioniert Authentifizierung?
Haben Sie eine Idee, wie wir unsere Website verbessern können?
Bitte schreiben Sie uns.
© 2025 De Gruyter Brill
Heruntergeladen am 22.9.2025 von https://www.degruyterbrill.com/document/doi/10.1515/chem-2016-0033/html
Button zum nach oben scrollen