Volume 56, Issue 1

CeAuSn, Ce 3 Rh 4 Sn 13 , and Ce 3 lr 4 Sn 13 were prepared by reaction of the elements in an arc-melting furnace and subsequent annealing at 970 K for two weeks. The three stannides were investigated by X-ray powder and single crystal techniques. CeAuSn crystallizes with the NdPtSb type, space group P6 3 mc: a = 472.7(2), c = 771.6(3) pm, wR2 = 0.0230,208 F 2 values, 11 variable parameters, and BASF = 0.40(2). The gold and tin atoms form a pronounced two-dimensional [AuSn] polyanion which consists of slightly puckered Au 3 Sn 3 hexagons. , 19 Sn Mössbauer data at 78 K show one signal at an isomer shift of δ = 1.90(7) mm/s subjected to unresolved quadrupole splitting of ΔE Q = 0.55(2) mm/s. Ce 3 Rh 4 Sn 13 and Ce 3 lr 4 Sn 13 adopt the cubic Yb 3 Rh 4 Sn 13 type structure, space group Pm3n: a = 970.51(3) pm, wR2 = 0.0721, 267 F 2 values (Ce 3 Rh 4 Sn 13 ) and a = 972.29(6) pm, wR2 = 0.0850, 267 F 2 values (Ce 3 lr 4 Sn 13 ) with 14 variable parameters for each refinement. Striking structural motifs in Ce 3 Rh 4 Sn 13 are condensed distorted trigonal [RhSn 6 ] prisms with Rh-Sn distances of 266 pm. The polyhe­dral network leaves two different cages which are occupied by cerium (6c position) and tin (2a position) atoms. The Sn2 atoms show occupancy parameters of only 92% (Ce 3 Rh 4 Sn 13 ) and 76% (Ce 3 Ir 4 Sn 13 ) and an extremely large displacement parameter indicating a rattling of these atoms within the icosahedral Sn 12 cages. Magnetic susceptibility measurements of Ce 3 Rh 4 Sn 13 show paramagnetic behavior down to 2 K with an experimental magnetic moment of 2.45(2) μ B /Ce. No magnetic ordering is observed. Magnetization measurements show a moment of 0.78(2) μ B /Ce at 2 K and 5.5 T. Resistivity data reveal only a very weak tem­perature dependence. The two crystallographically different tin sites are resolved in the 119 Sn Mössbauer spectrum which shows a signal at δ = 2.12(1) mm/s subject to quadrupole splitting of 1.54(1) mm/s, superimposed by a singlet at δ = 2.47(1) mm/s. The Seebeck coefficient of Ce 3 Rh 4 Sn 13 is within a few μ V/K of zero over the temperature range of 10 - 300 K.

Sodium pentacyanoferrates(III) of the type Na 2 [Fe(CN) 5 L] (L = phosphane or phosphite) have been prepared from sodium pentacyanoferrates(II), Na 3 [Fe(CN) 5 L], by bromine oxidation and characterized by Mössbauer, IR, and electronic spectroscopy. Isomer shifts and quadrupole splittings lie within the range commonly found in low-spin iron(III) complexes. A linear correlation was found between isomer shifts and CN stretching and Fe-CN bending frequencies, respectively. The spectroscopic parameters show that the d π -d π back bonding of the Fe-P bonds is synergetically strengthened with increasing σ donor capability of the phosphorus ligands.

The structures of tri-and tetraiodo-substituted carbon compounds are determined either expe­rimentally by X-Ray Structure Analysis or, because crystallization of tetraiodothiophene could not be achieved, approximated by Density Functional Theory optimization of structural data from a donor/acceptor complex. The structures show noteworthy details such as a second po­lymorph of tetraiodoethene crystallized by sublimation or herringbone crystal packing patterns of tetraiodopyrrole derivatives. All molecular geometries are discussed and compared based on relativistic density functional theory calculations with 6 -31G* basis sets including iodine pseudopotentials. They reproduce even finer structural details due to van der Waals repulsion of the bulky iodo substituents. Natural Bond Orbital (NBO) charge distributions suggest positive partial charges at all iodine centers with the strongest polarization Cδ ㊀ → Iδ ㊉ in HCI3, which contains well over 97% iodine.

Starting with the chiral pool compounds (-)-menthone, (-)-limonene, (-)-β-pinene, and (-)-carvone, new homochiral triethanolamine derivatives were obtained and converted to chi­ral silatranes. These silatranes were characterized by crystal structure analyses and NMR techniques. Conformational analyses in the solid state and in solution show that the chiral terpene residues determine the direction of the ring puckering of the silatrane moiety.

Dichloroiodate Tetraphenylphosphonium dichloroiodate(I) [PPh 4 ] [ICl 2 ] crystallises in the monoclinic system in the space group P2/n with a = 1025.7(1), b = 770.2(1), c = 1446.4(1) pm, ß = 90.11(1)° and two formula units per unit cell. The ICl 2 - anion is symmetrical (C 2v ) and almost linear with I-Cl bond lengths of 257.1(2) pm and a bond angle of 178.10(6)°.

Linear Trinuclear Nickel(II) Complex, Super-Exchange Interactions, Antiferromagnetic Coupling [Ni 3 (C 2 H 32 (CH 3 O) 2 L 2 ] [L = 13-bis(5-chlorosalicylideneamino)propan-2-ol dianion, (C 2 H 3 O 2 ) - = acetate, (CH 3 OH) = methanol] was synthesized and its crystal structure was determined. It crystallizes in the monoclinic spaceeroup P2 1 /n with a = 12.694(2), b = 13.281 (4), c = 15.420(3) Å, β = 111.25(2)°, V = 2422.9(9) Å 3 ,Z = 2 . The molecule is a "linear" trinuclear complex with nearly octahedral coordination of each nickel ion. Adjacent nickel(II) ions are bridged by the phenolic oxygen atoms of the ligands and the oxygen atoms of the acetato ligands. The coordination sphere of the terminal nickel(II) ions is completed by the oxygen atom of the methanol. Adjacent nickel(II) centers are separated by 3.043(1) Å and weakly antiferromagnetically coupled (J 1 = -3 .4 cm -1 ). The terminal nickel(II) centers are separated by 6.086(1) Å and very weakly antiferromagnetically coupled (J 2 = -0 .3 cm -1 ) which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.5 to 318 K. The magnetic moment rises from 2.99 μ B at 4.5 K to 5.42 μ B at 318 K. In the X (T) curve no characteristic maximum was observed.

Molten Salt Fluxes, Polychalcogenide, Polyselenide Na 2 Ti 2 Se 9 was first discovered in the quaternary system Na/Ti/P/Se, but it can be prepared rationally by dissolving Ti in a Na 2 Se x flux at 375 °C. The silverish dark red crystals are air-and water-stable. A new method for synthesizing Na 4 TiSe 4 is also reported. Na 2 Ti 2 Se 9 crystallizes in space group P2 1 , with a = 12.785(4), b = 14.848(4), c = 13.961(4) Å, ß = 94.556(4)°, R1 = 0.0592 and wR2 = 0.1336. The structure is similar to that of KsNaTi 6 Se 27 . It contains infinite one dimensional chains which run parallel to the c-axis and contain Ti 4+ centers bonded to Se 2 2- and Se 2- species. The l/∞[Ti 2 (Se 2 ) 4 Se] 2- chains pack together in a hexagonal pattern. All of the titanium atoms are surrounded by a pentagonal bipyramid of selenium atoms. The selenium atoms bridge the Ti centers in two different ways. Na 2 Ti 2 Se 9 is a semiconductor with a band gap, E g , of ~ 1.02 eV. The Raman spectra are also reported.

Using 1-chlorodecane (C 10 H 21 CI), benzyl chloride (C 6 H 5 CH 2 CI), a,a'-dichloro-p-xylene (CICH 2 C 6 H 4 CH 2 CI), 4-phenylbenzyl chloride (C 6 H 5 C 6 H 4 CH 2 CI), 2-bromomethyl-naphthal-ene (C 10 H 7 CH 2 Br), 4-bromomethyl-7-methoxycoumarin (C 10 H 7 O 3 CH 2 Br), 2-bromomethyl-anthraquinone (C 14 H 7 CH 2 Br), 9-chloromethyl-anthracene (C 14 H 9 CH 2 CI), thiourea and halides as starting materials, the organic-inorganic hybrid compounds [C 10 H 21 SC(NH 2 ) 2 ] 2 Pbl 4 , [C 6 H 5 CH 2 SC(NH 2 ) 2 ] 4 Pb 3 l 10 [(H 2 N 2 )CSCH 2 C 6 H 4 CH 2 SC(NH 2 ) 2 ] 0.5 PbI 3 , [C 6 H 5 C 6 H 4 CH 2 S-C(NH 2 ) 2 ]PbI 3 , [C 10 H 7 CH 2 SC(NH 2 ) 2 ]Pbl 3 , [C 14 H 7 O 2 CH 2 SC(NH 2 ) 2 ]Pbl 3 , [C 14 H 9 CH 2 SC(NH 2 ) 2 ]PbI 3 , and [C 14 H 9 CH 2 SC(NH 2 ) 2 ]PbBr 4 , were prepared and characterized analytically and spectroscopically.

The N-glycosyl-iminocarboxylate complexes Cp*M(Cl)N(R)=C(R')CO 2 (M = Rh, Ir; R = glycosyl, R ’ = Me, Ph, CH 2 CHMe 2 ) with a chiral metal atom are formed in a template reaction from [Cp*MCl 2 ] 2 (M = Rh, Ir), the 2-keto carboxylic acid and tetra-O-acetyl-β-Dglucosamine, D-glucosamine or D-glucamine as mixtures of two diastereoisomers and were characterized by analytical and spectroscopic methods.

From 2-amino-2-deoxy-D-gluconic acid (LH) and chloro bridged metal complexes the N,O chelates (R 3 P)(Cl)Pd(L) (R = n-C 4 H 9 , Ph), (n-C 4 H 9 ) 3 P(Cl)Pt(L), (C 6 H 4 CH 2 NMe 2 )Pd(L), (Ph-N=N-C 6 H 4 )Pd(L), Cp*(Cl)Ir(L) are formed. They were characterized by analytical and spectroscopic data.

Hydroboration of phenyl- and mesitylethyne with in situ formed HBCl 2 leads to an isomeric mixture of 1,1-bis(dichloroboryl)-2-phenylethane (4a) and l,l-bis(dichloroboryl)-1-phenylethane (4b) (ratio 3 : 1) and regioselectively to 1,1-bis(dichloroboryl)-2-mesitylethane (4c). Treatment of 4a/b and 4c with BI 3 gives the corresponding tetraiodo compounds 5, which undergo redox reactions with butyne-2 to form the 1,3-diiodo-4,5-dimethyl-2,3-dihydro-1,3- diborole derivatives 6a/b and 6c. Reactions of the diiodo-1,3-diboroles with AlMe 3 or LiMe result in the formation of the very air-sensitive pentaorganyl-1,3-diboroles 1a, 1c and the hexaorganyl-1,3-diborole 1b. The mixture of 1a/b as well as 1c react with bis(η 3 -allyl)nickel to give black products, which are chromatographed on silica with hexane as eluent. The brown solids were recrystallized from pentane to give the light-brown crystals of μ-η 5 ,η 5 -[2-benzyl-l,3 ,4 ,5 -tetramethyl-2 ,3-dihydrol, 3-diborolyl](η 3 -allyl)(η 4 -1,5-hexadiene)dinickel (2a, 34%) and μ-η 5 ,η 5 -[2-(2 ,4 ,6-trimethylbenzyl)- 1,3 ,4 ,5-tetramethyl-2 ,3-dihydro-1,3-diborolyl](η 3 -allyl)(η 4 -1,5-hexadiene)dinickel (2c, 43%). lb does not react with Ni(C 3 H 5 ) 2 to form any tripledecker. The compositions of the new compounds follow from spectroscopic and analytical data, and from X-ray structure analyses of 6a and of 2a. The structure of the η 4 -1,5-hexadiene-η 3 -allyl-dinickel triple-decker 2a finally disproved the alternative tris(allyl)dinickel arrangement.

Thioantimonates, Solvothermal Synthesis, Chalcogenides The reaction of elemental manganese, antimony and sulfur with ethylamine under mild solvothermal conditions yielded a thioantimonate(III) with composition Mn 2 (EA) 2 Sb 2 S 5 (EA = C 2 H 5 NH 2 ) that is a new member of a series of polymeric manganese thioantimo-nates(III). The structure of the title compound consists of layers of a neutral mesh-like Mn2Sb2S5 framework. The ethylamino ligands coordinated to the Mn centres separate the sheets and fill the voids within the layers formed by the interconnection of Mn 2 Sb 2 S 4 hetero-cubane like building blocks. Below 273 K a reversible phase transition occurs, which is accom­panied by a doubling of the crystallographic a-axis.

By reduction of [B 6 Cl 5 (p-C 6 H 4 (NO 2 ))] 2- with hydrazine in the presence of Raney nickel in dichlorom ethane solution the amino derivative [B 6 Cl 5 (p-C 6 H 4 (NH 2 )] 2- is formed. X -ray diffraction analysis has been performed on a single crystal of (Ph 4 P) 2 [B 6 Cl 5 (p-C 6 H 4 (NH 2 ] ·2CH 3 CN-0,5Et 2 O(triclinic, space group P1̅, a = 12.870(6), b = 12.9406(5), c = 35,870(7) Å , a = 91,63(4), ß = 93,22(7), γ = 98,04(8)°, Z = 2). The 11 B NMR spectrum is consistent with a monosubstituted B 6 cluster. The IR and R am an spectra exhibit characteristic BB, CH , CC, and NH vibrations, respectively.

[Si(N(CH 3 ) 2 ) 2 (NLiC(CH 3 ) 3 ) 2 ] 2 results from the reaction of silicon tetrachloride with excess terf-butylamine, followed by halogen substitution with LiN(CH 3 ) 2 , and treatment with n-butyllithium in hexane. The title compound, found to be dimeric in the solid state, was characterised by single crystal X-ray diffraction (triclinic, Pi , a = 10.208(2), b = 12.140(2), c = 15.658(3) Å , a = 79.02(3), ß = 82.80(3), γ = 67.19(3)°, Z = 2, C 24 H 60 Li 4 N 8 Si 2 ), and by solid state and solution NMR-spectroscopy and mass spectrometry.

The tris(alkinyl)phosphine complexes {(PhC=C) 3 P} 3 M(CO) 3 , M = Cr (3a), Mo (3b), W (3c), are obtained from P(C=CPh) 3 and (C 6 H 15 N 3 )M(CO) 3 (C 6 H 15 N 3 = 1,3,5-trimethyl-1,3,5-triazacyclohexane) as stable yellow solids in good yields. While IR data indicate significant acceptor properties of the phosphane ligands, the X-ray structure analysis of 3c also allows the discussion of weak donor interactions.

The coordination of the dicyanomethanidonitrite group through the nitroso oxygen atom in the tetrakis(pyridine) complexes [M{ONC(CN) 2 } 2 (py) 4 ], M = Ni, Co, Cu, and in the bis(pyridine) complex [Cu{ONC(CN) 2 } 2 (py) 2 ] was proved by X-ray crystallography of the Ni 11 complex and re-evaluated infrared spectra. The Ni 11 and Co 11 complexes exhibit almost octahedral structures composed of four pyridine nitrogen atoms and two oxygen atoms of dicyanomethanidonitrite ions. Both copper(II) complexes display a considerable axial distortion of the pseudooctahedral arrangement. In the bis(pyridine) Cu 11 complex the ONC(CN) 2 groups are involved in the bridging function by use of the oxygen and nitrile nitrogen atoms.

The preparation of tris(diformylamino)methane (3), a hitherto unknown derivative of orthoformic acid, is described. In the presence of a Lewis acid the orthoamide 3 formylates activated aromatic compounds.

An isotope effect of about -0.8 Hz at 188 MHz ( - 4 ppb) per two mass units on the 19 F chemical shift in Me 2 GeF 2 due to directly bonded 70 Ge/ 72 Ge/ 74 Ge/ 76 Ge has been observed. The analogous isotope effect on the 13 C chemical shift in Me 4 Ge is about -0.045 Hz at 100.6 MHz (-0.45 ppb).