Volume 73, Issue 11 - Special Issue: Dedicated to Professors Bernt Krebs and Werner Uhl of the Westfälische Wilhelms-Universität Münster

The crystal structure of pyridinium 6-methyl-1,2,3,-oxathiazine-4(3 H )-one-2,2-dioxide [(C 5 NH 6 )(C 4 H 4 NO 4 S)], for short, pyH(ace), was determined by X-ray diffraction methods. It crystallizes as a twin in the monoclinic space group P 2 1 / c with a =6.9878(9), b =7.2211(7), c =21.740(2) Å, β =91.67(1)° and Z =4 molecules per unit cell. The structure was determined employing 1599 reflections with I > 2 σ ( I ) from one of the twin domains and refined employing 2092 reflections from both crystal domains to an agreement R1 factor of 0.0466. Besides electrostatic attractions, intermolecular pyH···O=C(ace) hydrogen bonds stabilize the acesulfamate anion and the pyridinium cation into planar discrete units parallel to the (100) crystal plane. The units form stacks of alternating ace − and pyH + ions along the a axis that favors inter-ring π–π interactions. The Fourier transform-infrared (FT-IR) spectrum of the compound was recorded and is briefly discussed. Some comparisons with related pyridinium saccharinate salts are also made.

The synthesis of the tri-coordinated ferrocenecarbonitrile silver(I) complex [Ag(N≡CFc) 3 ]OTf ( 3 ) is reported. Its electrochemical behavior shows that the three ferrocenyl units are oxidized in a very close potential range. In addition, the molecular structure of 3 in the solid state is discussed, showing that silver(I) is exclusively coordinated by three ferrocenecarbonitrile molecules.

The ternary rare earth transition metal-indides RE 3 T 2 In 4 ( RE =Dy–Tm; T =Pd, Ir) were obtained from high-temperature reactions in sealed niobium ampoules. These indides adopt a hexagonal structure of the Lu 3 Co 1.87 In 4 type (space group P 6̅), a ternary ordered superstructure of the aristotype Fe 2 P. The structures of three different compounds were refined from single-crystal X-ray diffractometer data: a =768.20(6), c =381.97(3) pm, 1441 F 2 values, 24 parameters, wR 2=0.0338 (Ho 3 Pd 1.90 In 4 ); a =774.98(3), c =378.51(2) pm, 577 F 2 values, 23 parameters, wR 2=0.0742 (Ho 3 Ir 1.69 In 4.31 ) and a =780.3(1), c =369.4(1) pm, 573 F 2 values, 22 parameters, wR 2=0.0403 (Tm 3 Ir 1.51 In 4.49 ). Refinements of the occupancies revealed homogeneity ranges in case of the iridium-based crystals resulting from Ir/In mixing. The refined composition of the palladium compound was Ho 3 Pd 1.90 In 4 resulting from defects on the Wyckoff position 1 d , which was already reported for the prototype Lu 3 Co 1.87 In 4 . The geometrical motifs of the RE 3 T 2 In 4 structures are three different types of tricapped trigonal prisms around the transition metal and indium atoms which are condensed via common edges and triangular faces. Temperature dependent magnetic susceptibility measurements of Dy 3 Ir 2 In 4 and Tm 3 Ir 2 In 4 showed Curie-Weiss behavior and the experimental magnetic moments of 10.59(2) μ B (Dy 3 Ir 2 In 4 ) and 7.40(2) μ B (Tm 3 Ir 2 In 4 ) confirming stable trivalent RE 3+ states. Dy 3 Ir 2 In 4 and Tm 3 Ir 2 In 4 order antiferromagnetically with Néel temperatures of T N =13.6(5) and 5.4(5) K, respectively.

The first mixed germanato-antimonato derivative of the {V 14 E 8 O 42 } (E=semi-metal) cluster archetype has been synthesized under hydrothermal conditions and isolated as {Ni(phen) 3 } 2 [α-V IV 14 Sb III 5 Ge IV 3 O 42 (OH) 3 (H 2 O)]· ≈16H 2 O (phen=1,10-phenanthroline). In the cluster anion, seven of the eight hetero-metal positions are occupied by disordered Ge/Sb atoms, while one position is fully occupied by Sb atoms. The [V 14 Sb 5 Ge 3 O 42 (OH) 3 (H 2 O)] 6− anions are arranged in pairs with remarkably short inter-cluster Sb···O contacts. Bond valence sum calculation strongly suggests that the Sb···O contact must be taken into account as a weak bond. The magnetic properties are dominated by strong intra-cluster antiferromagnetic exchange interactions, and the cluster anion is magnetically quasi-isolated from the spins of the Ni 2+ complex cations.

A label for amino and thiol functionalities of peptides and proteins based on the activated cobaltocinium hexafluorophosphate succinimide ester (CoS) is presented. Despite the known selectivity of a succinimide ester towards amines, CoS also modifies cysteine residues under the same reaction conditions. The derivatized biomolecules were investigated using liquid chromatography with subsequent electrospray-mass spectrometric detection (LC/ESI-MS). In combination with their remarkable stability under physiological conditions, easy handling and good spectroscopic properties, cobaltocinium ions provide all requirements for a powerful labeling reagent. Furthermore, in direct comparison to the isoelectronic well-established ferrocene reagents, the higher redox potential and the chemical stability of the cobaltocinium moiety add to the benefits as a derivatizing agent for bioanalysis.

Reaction of Mn(NCS) 2 with pyrazole leads to the formation of three compounds with the compositions Mn(NCS) 2 (pyrazole) 4 ( 1 ), [Mn(NCS) 2 ] 2 (pyrazole) 6 ( 2 ) and Mn(NCS) 2 (pyrazole) 2 ( 3 ). Compound 1 , already reported in the literature, consists of discrete complexes, in which the Mn(II) cations are octahedrally coordinated by four pyrazole ligands and two terminally N-bonded thiocyanate anions. In compound 2 each of the two Mn(II) cations are coordinated octahedrally by three pyrazole ligands and one terminal as well as two bridging thiocyanate anions, which link the metal cations into dimers. In compound 3 also octahedrally coordinated Mn(II) cations are present but they are linked into chains via centrosymmetric pairs of μ -1,3-bridging thiocyanate anions. Upon heating compound 1 loses the pyrazole co-ligands stepwise and is transformed into the chain compound 3 via the dimer 2 that is formed as an intermediate. Magnetic measurements on compounds 2 and 3 reveal dominating antiferromagnetic interactions, as already observed for 1D Mn(NCS) 2 coordination compounds with pyridine based co-ligands.

A new calcium iron ruthenium hydrogarnet with the approximate composition Ca 3 (Ru 2− x Fe x )(FeO 4 ) 2− y (H 4 O 4 ) 1+ y ( x =1, y ≈0.35) has been obtained by hydrothermal synthesis under oxidizing alkaline conditions. The compound crystallizes in the cubic space group Ia 3̅ d (No. 230) with a lattice parameter of a =12.4804(4) Å ( T =100 K) and Z =8. The octahedral site of the garnet structure is equally occupied by Ru and Fe, whereas the tetrahedral site is partially occupied by Fe only. A partial substitution of the oxide anions by hydroxide ions is necessary for charge balancing, corresponding to the so-called hydrogarnet defects. The presence of hydroxide groups is proven by infrared spectroscopy. 57 Fe Mössbauer spectroscopic data provide evidence for two different Fe 3+ coordination environments as well as a magnetic ordering of two iron substructures with the respective ordering temperature above room temperature. The crystal composition was verified by energy-dispersive X-ray spectroscopy and the thermal behavior of the calcium iron ruthenate was studied by difference thermal analysis.

Two dinuclear metal complexes bearing the purine derivative 7-methyl-6-furylpurine ( 1b ) as a ligand are reported. In [Ag 2 ( 1b ) 2 (DMSO) 2 ](ClO 4 ) 2 ·DMSO and [Cu 2 ( 1b ) 2 (NO 3 ) 2 ], two bridging purine derivatives coordinate the two metal ions via their N3 and N9 positions. In the silver(I) complex, the coordination environment of each metal ion is completed by a DMSO ligand, whereas an additional nitrato ligand coordinates to each copper(I) ion. The intramolecular Ag···Ag distance of 3.1069(5) Å is in agreement with the presence of a weak argentophilic interaction, whereas the Cu···Cu distance of 2.9382(4) Å is too long to be indicative of a cuprophilic interaction. The compounds represent the first examples of dinuclear complexes comprising two N3,N9-bridging purine derivatives without any additional bridging ligand.

Several rare earth metal containing pseudo-ternary compounds in the RE 2 T Al 3 series ( RE =Sc, Y, La–Nd, Sm, Gd–Lu; T =Ru, Rh, Ir) have been synthesized from the elements by arc-melting or in tantalum capsules. Within the Rh series, the compounds with RE =La–Nd crystallize in the cubic MgCu 2 -type ( Fd 3̅ m ) structure. For Sm besides the cubic Laves phase also the hexagonal Laves phase (MgZn 2 type, P 6 3 / mmc ) is found. For the remaining compounds of both series, also the hexagonal MgZn 2 -type structure is observed. The structures of Ho 2 Ru 0.96(1) Al 3.04(1) ( a =547.4(1), c =875.7(1) pm, wR =0.0397, 201 F 2 values, 13 variables), Sc 2 Rh 1.01(1) Al 2.99(1) ( a =528.0(1), c =852.8(1) pm, wR =0.0228, 184 F 2 values, 13 variables), Ho 2 Rh 1.00(1) Al 3.00(1) ( a =546.5(1), c =873.8(1) pm, wR =0.0590, 222 F 2 values, 13 variables) and Tb 2 Ir 1.06(1) Al 2.94(1) ( a =550.8(1), c =870.0(1) pm, wR =0.0743, 221 F 2 values, 13 variables) have been refined from single-crystal data, indicating T /Al mixing on both crystallographic Zn sites of the aristotype. The Sc, Y, La and Lu containing compounds exhibit Pauli-paramagnetic behavior, while the other compounds show paramagnetism, in line with the rare earth atoms in the trivalent oxidation state. Ferro- and antiferromagnetic ordering up to T C =50.2(1) K for Gd 2 RhAl 3 is observed, while Sm 2 RuAl 3 shows van Vleck paramagnetism and Yb 2 RuAl 3 , finally, exhibits only partially trivalent Yb atoms, evident from a reduced magnetic moment and increased lattice parameters.

A new stacking variant of sodium hexa-hydroxo platinate(IV), Na 2 Pt(OH) 6 , was synthesized and its structure elucidated through X-ray diffraction. The new polymorph was prepared by direct reaction of PtO 2 with an excess of NaOH solution applying elevated oxygen pressure at 300°C. The structure consists of layers of edge sharing Pt(OH) 6 and Na(OH) 6 octahedra. These layers are separated by an edge-to-edge distance of ~2.4 Å. The packing of the hydroxide ions corresponds to the hcp sequence, the title compound thus may be regarded a cation ordered variant of the Brucite structure type. During heating above T ~300°C all constitutional water is released, and anhydrous Na 2 PtO 3 remains as the solid residue.

The six isotypic alkali ortho chalcogenido manganates A 6 [Mn II Q 4 ] ( A =Rb, Cs; Q =S, Se, Te) were synthesized – in most cases in pure phase – from stoichiometric mixtures of the manganese monochalcogenides Mn Q , the elemental chalcogens and Rb 2 S/Cs 2 S 2 (sulfido salts) or the pure alkali elements (selenido and tellurido salts) as alkali sources at maximum temperatures between 650 and 800°C. Their hexagonal crystal structures were refined by means of X-ray single crystal data (space group P 6 3 mc , Na 6 ZnO 4 -type structure, Z =2; A / Q : Rb/S: a =1019.34(2), c =792.560(10) pm, R 1=0.0166; Rb/Se: a =1055.74(2), c =821.14(2) pm, R 1=0.0275; Rb/Te: a =1126.68(2), c =860.54(2) pm, R 1=0.0152; Cs/S: a =1056.68(2), c =831.22(2) pm, R 1=0.0168; Cs/Se: a =1096.04(3), c =858.13(2) pm, R 1=0.0194; and Cs/Te: a =1167.72(3), c =896.95(2) pm, R 1=0.0140). The chiral structures contain isolated C 3 symmetric, but very close to ideal tetrahedral, ortho manganate(II) anions [Mn II Q 4 ] 6− with Mn– Q distances of 248.7–250.7 ( Q =S), 260.7–263.0 ( Q =Se) and 280.0–282.4 pm ( Q =Te). The chalcogenide ions form a hexagonal closed packing with slightly puckered 3 6 nets, in which the A (2) cations occupy 3/4 of the octahedral interstices, whereas Mn takes 1/8 and A (1) 3/8 of the tetrahedral voids. Magnetic measurements on the three Cs compounds showed Curie-Weiss behavior down to a temperature of 1.9 K, with magnetic moments significantly reduced with respect to the expected spin-only value of a d 5 ion. The electronic band structures of the four salts (Na/Rb) 6 Mn(S/Te) 4 , which were calculated within the GGA+ U approach, allow a comparison of the chemical bonding characteristics and the magnetic properties within the alkali cation and the chalcogenido ligand series.

Herein, we present three new tetradentate C^N*N^C luminophores and their platinum(II) complexes. We describe the influence of the degree of fluorination at the phenylpyridine luminophore on the photophysical properties of the monomeric species. A blue-shift can be observed with increasing number of fluorine atoms (0–6), which is related to a growing HOMO-LUMO gap that reaches a maximum for four halogen moieties. Increasing degree of fluorination enables intermolecular Pt–Pt interactions and promotes emission from 3 MMLCT states in amorphous solids and matrices, with the drawback of lowered solubility. A clear trend towards layered packing patterns in crystals has been observed within the series. This knowledge is important for the design and realization of triplet emitters with aggregation-controlled luminescence towards potential applications in optoelectronic devices.

Rutile-type nanorods of SnO 2 were obtained in a one-pot hydrothermal synthesis starting from SnCl 4 ·5H 2 O and HCl in a temperature range between 200 and 240°C. Although the nanorods are polydisperse, the average length of the nanorods could be adjusted from 13 to 65 nm by varying of the reaction temperature. The resulting anisotropic nanocrystals were characterized using powder X-ray diffraction (PXRD), (high resolution-) transmission electron microscopy (HR-TEM), and selected area electron diffraction (SAED). The particle growth proceeds via a dissolution-recrystallization process with soluble [SnCl 5 (H 2 O)] − intermediates, as confirmed by PXRD, Raman spectroscopy, and magic angle spinning nuclear magnetic resonance (MAS-NMR).

The stannides RE Ir 2 Sn 4 ( RE =La, Ce, Pr, Nd, Sm) were synthesized from the elements by arc melting or by induction melting in sealed niobium containers. They crystallize with the NdRh 2 Sn 4 type structure, space group Pnma . The samples were characterized by powder X-ray diffraction (Guinier technique). Three structures were refined from single-crystal X-ray data: a =1844.5(2), b =450.33(4), c =716.90(6) pm, wR 2=0.0323, 1172 F 2 values, 44 variables for LaIr 2 Sn 4 , a =1840.08(2), b =448.24(4), c =719.6(1) pm, wR 2=0.0215, 1265 F 2 values, 45 variables for Ce 1.13 Ir 2 Sn 3.87 , and a =1880.7(1), b =446.2(1), c =733.0(1) pm, wR 2=0.0845, 836 F 2 values, 45 variables for Ce 1.68 Ir 2 Sn 3.32 . The structures consist of three-dimensional [Ir 2 Sn 4 ] polyanionic networks in which the rare earth atoms fill pentagonal prismatic channels. The striking structural motif concerns the formation of solid solutions RE 1+ x Ir 2 Sn 4− x on the Sn4 sites, which have similar coordination as the RE sites. Temperature dependent magnetic susceptibility measurements revealed diamagnetic behavior for LaIr 2 Sn 4 . CeIr 2 Sn 4 , PrIr 2 Sn 4 and NdIr 2 Sn 4 show Curie-Weiss paramagnetism while SmIr 2 Sn 4 exhibits typical van Vleck paramagnetism. Antiferromagnetic ground states were observed for CeIr 2 Sn 4 ( T N =3.3 K) and SmIr 2 Sn 4 ( T N =3.8 K). 119 Sn Mössbauer spectra show a close superposition of four sub-spectra which can be distinguished through their isomer shift and the quadrupole splitting parameter.

Two new cationic DNA intercalators, 3-phenyl-1-(6-phenylpyridin-2-yl)-1 H -[1,2,4]triazolo[4,3- a ]pyridin-4-ium ( 1a ) + and 1-phenyl-3-(6-phenylpyridin-2-yl)-3 H -[1,2,4]triazolo[4,3- a ]quinolin-10-ium ( 1b ) + , were synthesized from 2-chloropyridine and 2-chloroquinoline, respectively, in a four-step procedure. Generation of the hydrazine, followed by condensation with an aldehyde to give a hydrazone and subsequent Buchwald-Hartwig amination gave a mixture of E - and Z -configured N , N -functionalized hydrazones. Finally, oxidative cyclisation gave rise to the formation of the cationic DNA intercalators, whose molecular structures were determined by single-crystal X-ray diffraction analysis of the hexafluorophosphate and tribromide salt of ( 1a ) + and ( 1b ) + , respectively. The intercalative binding of ( 1a )PF 6 and ( 1b )PF 6 to ctDNA was confirmed by means of UV, CD and luminescence spectroscopy, determination of the DNA melting temperature and by rheology measurements.

We report the synthesis of functionalized 1,3-bis(diphosphacyclobutadiene) complexes via the insertion of carbon-oxygen bonds of ethers, esters, aldehydes and amides into the P–Si bond of silylated complexes. Reactions of [K(tol) 2 ][Co( η 4 -P 2 C 2 R 2 ) 2 ] [ [K(tol) 2 ][1a]: R= t Bu, [K(tol) 2 ][1b]: R= t Pent (= tert -pentyl)] with Me 3 SiCl afford the trimethylsilyl-substituted derivatives [Co( η 4 -P 2 C 2 R 2 SiMe 3 )( η 4 -P 2 C 2 R 2 )] ( 2a, b , R= t Bu, t Pent). The Me 3 Si group is connected to a phosphorus atom of one of the 1,3-diphosphacyclobutadiene ligands. 2a, b readily react with organic substrates containing C–O single and C=O double bonds at ambient temperature. [Co( η 4 -P 2 C 2 R 2 (CH 2 ) 4 OSiMe 3 )( η 4 -P 2 C 2 R 2 )] ( 3a , b ) are formed by reaction of 2a , b with traces of THF. They can also be isolated by reacting the THF solvates [K(thf) 2 {Co(P 2 C 2 t Bu 2 ) 2 }] ( [K(thf) 2 ][1a] ) and [K(thf) 3 {Co(P 2 C 2 t Pent 2 ) 2 }] ( [K(thf) 3 ][1b] ) with Me 3 SiCl in toluene or THF. The adamantyl-substituted complex [Co( η 4 -P 2 C 2 Ad 2 (CH 2 ) 4 OSiMe 3 )( η 4 -P 2 C 2 Ad 2 )] ( 3c ) was prepared analogously from [K(thf) 4 {Co(P 2 C 2 Ad 2 ) 2 }] and Me 3 SiCl. [K(thf) 2 ][1a] reacts cleanly with Ph 3 SnCl affording [Co( η 4 -P 2 C 2 t Bu 2 SnPh 3 )( η 4 -P 2 C 2 t Bu 2 )] ( 4 ) in high yield. Reaction of 2a with styrene oxide affords [Co( η 4 -P 2 C 2 t Bu 2 PhC 2 H 3 OSiMe 3 )( η 4 -P 2 C 2 t Bu 2 )] ( 5 ) as a single regioisomer. By contrast, multinuclear NMR spectroscopic studies indicate mixtures of two isomeric insertion products 6/6 ′ and 7/7 ′, respectively, which result from the insertion of 1,2-epoxy-2-methylpropane and 1,2-epoxyoctane. Moreover, these monitoring studies show that reactions of 2a with acyclic ethers afford alkyl substituted complexes such as [Co( η 4 -P 2 C 2 t Bu 2 Et)( η 4 -P 2 C 2 t Bu 2 )] ( 8 ) and alkylsilyl ethers. Reaction of 2a with γ -butyrolactone gives [Co( η 4 -P 2 C 2 t Bu 2 (CH 2 ) 3 C(O)OSiMe 3 )( η 4 -P 2 C 2 t Bu 2 )] ( 9 ) via cleavage of the endocyclic C–O single bond of the lactone. Benzaldehyde and acetone cleanly react with 2a to [Co( η 4 -P 2 C 2 t Bu 2 CH(Ph)OSiMe 3 )( η 4 -P 2 C 2 t Bu 2 )] ( 10 ) and [Co( η 4 -P 2 C 2 t Bu 2 CMe 2 OSiMe 3 )( η 4 -P 2 C 2 t Bu 2 )] ( 11 ), while the sterically more demanding ketones 3-pentanone and acetophenone selectively yield the known hydride complex [Co( η 4 -P 2 C 2 t Bu 2 ) 2 H] ( A ). Phenyl isocyanate reacts with 2a at elevated temperature to form [Co( η 3 -P 2 C 2 t Bu 2 CON(Ph)SiMe 3 )( η 4 -P 2 C 2 t Bu 2 )] ( 12 ) with a functionalized η 3 -coordinated ligand. [K(tol) 2 ][1a] , [K(tol) 2 ][1b] , 2a , 2b , 3a–c , 4 , 5 , and 9–12 were isolated and characterized by multinuclear NMR spectroscopy, UV/Vis spectroscopy and elemental analysis. [K(tol) 2 ][1b] , 2a , 2b , 3c , 4 , 5 , and 9–12 were additionally characterized by X-ray crystallography.

Bis(trimethylsilyl)carbodiimide (BTSC), so-called “pseudo water” because of some analogies such as similar (group)electronegativities of Me 3 Si– vs. H– and –N=C=N– vs. –O–, may form two different kinds of “pseudo hydrates” of metals (M), i.e. M–N(SiMe 3 )=C=N(SiMe 3 ) and M–N≡C–N(SiMe 3 ) 2 , derived from its carbodiimide and cyanamide isomeric forms, respectively. With anhydrous AlCl 3 in Me 3 SiCl solution BTSC was shown to be capable of forming both kinds of solvates, i.e. Cl 3 Al–N(SiMe 3 )–C≡N(SiMe 3 ) ( 1 ) and ((Cl 3 Al)(Me 3 Si)NCN) 3 –Al–(N≡C–N(SiMe 3 ) 2 ) 3 ( 2 ). Both compounds were isolated as crystalline solids, which undergo condensation reactions upon storage. By single-crystal X-ray diffraction analysis the constitution of 1 was confirmed unambiguously, and quantum chemical calculations (B3LYP/6-311++g(d,p)) confirmed that compound 1 is 6 kcal mol −1 more stable than its hypothetical N , N -bis(trimethylsilyl)cyanamide isomer Cl 3 Al–N≡C–N(SiMe 3 ) 2 . Compound 1 represents the first crystallographically confirmed disilylcarbodiimide complex of a metal salt. The molecules of compound 2 are heavily disordered in the solid state (positional disorder of N≡C–N(SiMe 3 ) 2 vs. N≡C–N(SiMe 3 )(AlCl 3 ) and positional disorder of SiMe 3 vs. AlCl 3 groups in the latter). Therefore, the identity of 2 was additionally confirmed by 13 C, 15 N, 27 Al and 29 Si CP/MAS NMR spectroscopy.

The first ammonium indium borate (NH 4 )InB 8 O 14 was synthesized from indium oxide and boric acid under high-pressure/high-temperature conditions of 9 GPa and 1000°C with a Walker-type multianvil apparatus in a BN crucible. Although a reproduction of this synthesis product failed until now, we were able to determine the crystal structure via single-crystal X-ray diffraction data collected at room temperature. (NH 4 )InB 8 O 14 crystallizes in the monoclinic space group P 2/ m ( Z =2) with a =4.4053(2), b =7.8184(3), c =12.4685(4) Å, β =94.60(1)°, and V =428.06(3) Å 3 . The structure comprises all three basic structural units of borates, namely corner-sharing BO 4 tetrahedra, edge-sharing BO 4 tetrahedra, and planar BO 3 groups. Large cavities in the borate network give space to disordered, isolated ammonium ions. The presence of nitrogen (confirmed by EDX analysis) appears to originate from the container material.

The rare earth metal-rich cobalt and nickel aluminium compounds with the general compositions RE 6 Co 2 Al ( RE =Sc, Y, Nd, Sm, Gd–Tm, Lu) and RE 6 Ni 2.25 Al 0.75 ( RE =Y, Gd–Tm, Lu) have been synthesised from the elements by arc-melting, followed by annealing. Single-crystal X-ray diffraction experiments on Y 6 Co 2.02(1) Al 0.98(1) (Ho 6 Co 2 Ga type; Immm ; a =944.1(2), b =952.4(2), c =999.0(2) pm; wR 2=0.0452, 1123 F 2 values, 35 variables) and Y 6 Ni 2.26(1) Al 0.74(1) (Ho 6 Co 2 Ga type; Immm ; a =938.30(5), b =959.45(5), c =996.05(6) pm; wR 2=0.0499, 1131 F 2 values, 35 variables) revealed that the compounds form solid solutions according to the general formula RE 6 (Co/Ni) 2+ x Al 1− x with different homogeneity ranges. The compounds of the Ni series can be obtained in X-ray pure form only with the nominal composition RE 6 Ni 2.25 Al 0.75 . A significant increase of the U 22 component of the anisotropic displacement parameters of the Co/Ni2 atoms (4 g site) was observed that requires a description of the structure with a split-position model at RT. Further investigations by low temperature (90 K) single-crystal X-ray diffraction experiments of Y 6 Co 2.02(1) Al 0.98(1) showed a significant decrease of U 22 . Magnetic measurements were conducted on the X-ray pure members of the RE 6 Co 2 Al ( RE =Y, Dy–Tm, Lu) series. Antiferromagnetic ordering was observed for the members with unpaired f electrons with Néel temperatures up to T N =48.0(1) K and two spin reorientations for Dy 6 Co 2 Al.

The bulky phenols 2,6-Ad 2 C 6 H 3 OH (Ad=adamantyl), A , (2,6-Ph 2 CH) 2 -4-Me-C 6 H 2 OH, B , and (2,6-Tol 2 CH) 2 -4- i Pr-C 6 H 2 OH, C , react with one equivalent of Et 3 M (M=Al, Ga), Bu 2 Mg and Et 2 Zn to afford well-defined mono-phenolate complexes (ArOMR n ) m . The aluminum and gallium phenolates derived from the very bulky phenol A are likely monomeric in the solid state. The other compounds are dimeric with bridging phenolates. Crystal structures of compounds with phenols B and C display the dimeric M 2 O 2 cores of the phenolates and illustrate some deviations for the magnesium and zinc compounds. The former possesses stabilizing Mg···C contacts with one of the flanking arene groups of the phenolate substituent, and the latter may be viewed as an intermediate between a symmetric dimer and two monomers. All compounds were characterized by 1 H and 13 C NMR spectroscopy, and their solution spectra are in agreement with the crystal structure data.

The trifunctional silylamine MesSi(NHPh) 3 (Mes: 2,4,6-trimethylphenyl) was prepared by standard methods from MesSiCl 3 and LiNHPh. Lithiation of MesSi(NHPh) 3 and subsequent reaction with copper(I) benzoate afforded the nonanuclear cluster complex [Cu 9 {MesSi(NPh) 3 } 2 (PhCO 2 ) 3 ]·2toluene. The cluster core consists of three copper atoms which are coordinated almost linearly by the nitrogen atoms of two adjacing MesSi(NPh) 3 units. Additionally, each of the silylamide nitrogen atoms is connected to a peripheral copper atom and the peripheral copper atoms are linked by μ 2 - κ ( O , O ′) bridging benzoate groups. The observed Cu–N distances are in the range 189.6(4)–196.7(3) pm.