Gas-phase electron diffraction studies on two 11-vertex Dicarbaboranes, closo-2,3-C2B9H11 and nido-2,9-C2B9H13

The molecular structures of two carbaboranes, closo-2,3-C(2)B(9)H(11) and nido-2,9-C(2)B(9)H(13), were determined experimentally for the first time using gas-phase electron diffraction (GED). For closo-2,3-C(2)B(9)H(11), a model with C(2)(v)() symmetry was refined to give C-B bond distances ranging 158.3-167.0 pm and B-B distances ranging 177.4-200.0 pm. The structure of nido-2,9-C(2)B(9)H(13) was refined using a model with C(s)() symmetry to give C-B bond lengths ranging 160.3-171.9 pm and B-B lengths ranging 173.0-196.1 pm. Ab initio computations (up to MP2/6-311+G) were also carried out on these and the related nido-7,8-C(2)B(9)H(13), which was not sufficiently stable to allow determination of its molecular structure by GED.     

Synthesis of binuclear rhodacarboranes from 1,4-and 1,3-C6H4(CH2-9-C2H2B9H9-7,8-nido]2 2− dianions and (Ph3P)3RhCl

1,4- and 1,3-C₆H₄(CH₂-9-C₂H₂B₉H₉-7,8-nido]₂ ^2? dianions obtained fromnido-7,8-dicarbollide ion and 1,4-bis(bromomethyl)- and 1,3-bis(bromomethyl)benzenes react with (Ph₃P)₃RhCl to give binuclear rhodacarboranes, 1,4- and 1,3-[3,3-(Ph₃P)₂-3-H-3,1,2-RhC₂B₉H₁₀-4-CH₂]₂C₆H4.     

Darstellung und Kristallstrukturen von [P(C6H5)4][1-(NH3)B10H9] und Cs[(NH3)B12H11] · 2CH3OH

Synthesis and Crystal Structures of [P(C₆H₅)₄][1-(NH₃)B₁₀H₉] and Cs[(NH₃)B₁₂H₁₁] · 2CH₃OH The reduction of [1-(NO₂)B₁₀H₉]^2? with aluminum in alkaline solution yields [1-(NH₃)B₁₀H₉]^? and by treatment of [B₁₂H₁₂]^2? with hydroxylamine-O-sulfonic acid [(NH₃)B₁₂H₁₁]^? is formed. The crystal structures of [P(C₆H₅)₄][1-(NH₃)B₁₀H₉] (triclinic, space group P1 , a = 7.491(2), b = 13.341(2), c = 14.235(1) Å, α = 68.127(9), β = 81.85(2), γ = 86.860(3)°, Z = 2) and Cs[(NH₃)B₁₂H₁₁] · 2CH₃OH (monoclinic, space group P2₁/n, a = 14.570(2), b = 7.796(1), c = 15.076(2) Å, β = 111.801(8)°, Z = 4) reveal for both compounds the bonding of an ammine substituent to the cluster anion.     

High-pressure- and low-temperature-induced changes in [(CH3)2NH(CH2)2NH3][SbCl5

The structure of N,N-dimethylethylenediammonium pentachloroantimonate(III), [(CH3)2NH(CH2)2NH3][SbCl5], NNDP, was investigated at 100 and 15 K at ambient pressure, as well as at pressures up to 4.00 GPa at room temperature in the diamond-anvil cell. The stable structure at low temperatures and low pressures consists of isolated [SbCl5]2- anions and [(CH3)2NH(CH2)2NH3]2+ cations. The inorganic anions have a distorted square pyramidal geometry. They are arranged in linear chains parallel to the c axis. In contrast to the low-temperature studies, where no phase transition was detected, pressure induces a P2(1)/c --> P2(1)/n phase transition between 0.55 and 1.00 GPa, accompanied by a doubling of the a unit-cell parameter. This solid-solid transition results from changes in the electron configuration of the Sb(III) atom and formation of the Sb-Cl bridging bonds between inorganic polyhedra to form, at approximately 1.0 GPa, isolated [Sb2Cl10]4- units consisting of [SbCl6]3- octahedra and [SbCl5]2- square pyramids connected by a common corner. The intermolecular distances continuously decrease with further increase in pressure, and at approximately 3.1 GPa, zigzag [{SbCl5}n]2n- chains containing corner-sharing [SbCl6]3- octahedra are formed. The unit-cell volume of NNDP decreases by 18.15% between room pressure and 4.00 GPa. The linear distortions of the [SbCl5]2- and [SbCl6]3- polyhedra decrease with increasing pressure and decreasing temperature and indicate a reduction in the stereochemical activity of the lone electron pair on the Sb(III) atom.     

Isomeric ammonio derivatives of nido-carborane 3- and 10-H3N-7,8-C2B9H11

Abstract

Structure of 3-ammonio derivative of nido-carborane 3-NH₃-7,8-C₂B₉H₁₁ was determined by single crystal X-ray diffraction. The isomeric 10-ammonio derivative 10-NH₃-7,8-C₂B₉H₁₁ was prepared by the treatment of the corresponding ethylnitrilium derivative 10-EtC≡N-7,8-C₂B₉H₁₁ with hydrazine hydrate in acetonitrile.     

Synthesis,characterization and luminescence of the tetranuclear gold cluster: [Au4{7,8-(PPh2)2-7,8-C2B9H10}2(PPh3)2]

A tetranuclear gold cluster has been synthesized by the reaction of [Au(PPh₃)NO₃] with the closo carborane diphosphine 1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀ in THF, and characterized by elemental analysis, FT-IR, ¹H and ¹³C?NMR spectroscopy and X-ray structure determination. The cluster crystallizes in the triclinic Pī, a?=?15.118(8)?Å, b?=?16.057(9)?Å, c?=?24.284(13)?Å, α?=?80.822(9)°, β?=?79.624(8)°, γ?=?81.938(8)°, Z?=?2, R ₁?=?0.0626, wR ₂?=?0.1894. A single crystal structure determination showed that four gold atoms form a tetrahedral framework. Among these four gold atoms, two were chelated by two nido carborane diphosphine [7,8-(PPh₂)₂-7,8-C₂B₉H₁₀]^? anions coming from the degradation of the initial closo ligand 1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀, while the other two were ligated to two PPh₃ groups. The luminescence of this cluster was also investigated in dichloromethane solution at room temperature.     

Trimethylammonium-containing rhodacarborane [(9-NMe3-7,8-C2B9H10)RhCl2]2 as a catalyst for the annulation of arylcarboxylic acids with alkynes

Russian Chemical Bulletin - Rhodacarborane [(9-NMe3-7,8-C2B9H10)RhCl2]2 exhibited moderate catalytic activity in the reaction of annulation of arylcarboxylic acids with alkynes, giving naphthalenes...     

Crystal Structure,Thermal and Electric Behaviour of [(CH3)2NH2]3[As2Cl9] and [(CH3)2NH2][AsOCl2]

Single crystals of the organic‐inorganic arsenate(III): [(CH₃)₂NH₂]₃[As₂Cl₉] and [(CH₃)₂NH₂][AsOCl₂] have been grown from aqueous hydrochloric acid solution. The crystals [(CH₃)₂NH₂]₃[As₂Cl₉] have been investigated by X‐ray diffraction (at 253 K), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dilatometric and dielectric methods. They undergo two structural phase transitions of first order at 228/235 and 298/307 K (on cooling/heating), respectively, which are classified as an "order‐disorder" type. The trigonal [(CH₃)₂NH₂]₃[As₂Cl₉] structure (at 253 K, intermediate phase (II)) refined in the space group R3c, consists of isolated [As₂Cl₉]^3‐ bioctahedral units and dimethylammonium cations hydrogen bonded to the bridging Cl atoms of the anions. The crystals of [(CH₃)₂NH₂][AsOCl₂] at 100 K are orthorhombic, space group Cmca. The structure contains one‐dimensional chains formed by strong distorted [AsO₂Cl₄] octahedra. The dimethylammonium cations reveal distinct disorder.     

Deuteration of closo-1,2- and 1,7-C2B10H12 using C6D6/AlCl3: Mechanistic considerations

Regioselective deuteration of 1-X-C₂B₁₀H₁₂ (X = 2, 7) cage systems with C₆D₆/AlCl₃ is correlated to ab initio calculational results on a [C₂B₁₀H₁₃]⁺ intermediate. Full geometry optimizations of pertinent [C₂B₁₀H₁₃]⁺ isomers, derived from each of the two 1-X-C₂B₁₀H₁₂ carborane isomers, result in cage geometries not unlike the (nearly) icosahedral starting carborane. Each isomer contains a BH₂ group having an acute H-B-H angle, long B–H bonds, and a very short H · · · H distance, hinting that the pertinent boron shares the electrons of a hydrogen molecule σ pair. It is suggested that the structural differences between the BH₂ group of [C₂B₁₀H₁₃]⁺ and the CH₂ group of the benzenium ion, [C₆H₇]⁺ (the intermediate strongly intimated upon protonation of benzene), can be explained, in part, by (a) the availability of the π-ring electrons for bonding to the (extra) proton in the latter and (b) the unavailability of π electrons from the carborane. Thus, the C₂B₁₀H₁₂ cage is most probably very reluctant to give up a cage electron pair in order to assist in bonding to an (externally bound) proton. Instead, it is more probable that “hydridic” B–H sigma electrons could very well play the important role in providing bonding to the attacking proton. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:95–102, 1998     

Synthesis of 9-C6H5-3-(π-C5H5)-3,1,2-CoC2B9H10 by cross-coupling reaction of 9-I-3-(π-C5H5)-3,1,2-CoC2B9H10 with C6H5ZnCl catalyzed by palladium complexes

The cross-coupling reaction of 9-I-3-(π-C₅H₅)-3,1,2-CoC₂B₉H₁₀ with organozinc compounds catalyzed by palladium complexes was used to synthesize the first representative ofB-phenyl-substituted carboranes, 9-C₆H₅-3-(π-C₅H₅)-3,1,2-CoC₂B₉H₁₀. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No: 6, pp. 1253–1254, June, 1998.     

Synthesis and characterization of cyano-substituted carborane-based compounds. Molecular structure of [1-(4-C7H7)-12-(C5H3-3-(CN)-3,4-(CH3)2)-C2B10H10

The reaction of cyanogen chloride with [1-(4-C(7)H(7))-12-(C(5)H(3)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (7) was found to yield two new C(5)-substituted carborane cluster-based compounds, [1-(4-C(7)H(7))-12-(C(5)H(2)-3-(CN)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (8) and [1-(4-C(7)H(7))-12-(C(5)H-2,4-(CN)(2)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (9). This cyano-substitution pattern is in contrast to the known substitution for the analogous organic quinarene[5.6.7] system. The observed unique cluster-based products may be understood by a combination of steric and electronic effects. Compounds 8 and 9 were characterized by complete multinuclear NMR, (1)H-(1)H COSY NMR, (1)H-(13)C HMQC NMR, FTIR, UV-Vis, IR, MS data and a single crystal analysis for 8 [X-ray data for 8: C(17)H(25)B(10)N, monoclinic, space group P2(1)/n with cell constants a = 8.6794(17) ?, b = 11.021(2) ?, c = 43.175(9) ?, β = 91.00(3)°, V = 4129.2(14) ?(3), Z = 8, R(1) = 0.0729, wR(2) = 0.1464].     

[(NH2CH2CH2NH3)2WⅥO2(NHC6H4NH)2]2(NH2CH2CH2NH2)·H2O配合物的合成与晶体结构

Cis-dioxo-tungsten(Ⅵ) complex, (NH₂CH₂CH₂NH₂)[(NH₂CH₂CH₂NH₃)₂W^ⅥO₂(NHC₆H₄NH)₂]₂·H₂O is synthesized at room temperature by the reaction of sodium tungstate with o-phenylenediamine. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P2₁/ c, a=0.712 8(2) nm, b=3.081 1(10) nm, c=0.981 9(3) nm, β=102.615(4)°, V=2.104 4(11) nm³, Z=2, μ=55.26 cm^-1, F(000)=1 176. Compared the complex with its analogous biomimetic complexes of the cofactor of molybdoenzymes and tungstoenzymses, it is found that the variance of the coordination atoms and the metal ions center have no influence on the coordination feature, and exhibits distored octahedral coordination with cis-dioxo o-phenylenediamine. CCDC: 252834.     

Structure of 6,11-dichloro-9-dimethylthio-7,8-dicarba-nido-undecaborane [6,11-Cl2-9-SMe2-7,8-C2B9H9]

A technique is proposed for directed synthesis of 6,11-dichloro-9-dimethylthio-7,8-dicarba-nido-undecaborane [6,11-Cl₂-9-SMe₂-7,8-C₂B₉H₉]. Single-crystal X-ray diffraction is used to identify the molecular and crystal structure of the compound.     

Azatricarbaborane 7-t-Bu-arachno-7,1,5,12-NC3B8H12 and Parent Tricarbaboranes nido-[5,6,9-C3B7H10]- and -5,6,9-C3B7H11

The neutral azatricarbaborane 7-t-Bu-arachno-7,1,5,12-NC(3)B(8)H(12), isolated as a side product (yield 2%) from the new synthesis of 7-t-BuNH2-nido-7,8,9-C(3)B(8)H(10) (yield 70%), can be easily converted to the first parent representatives of the 10-vertex nido family of tricarbaboranes, [5,6,9-C(3)B(7)H(10)]- and 5,6,9-C(3)B(7)H(11).     

Sandwich iridium complexes with the monoanionic carborane ligand [9-SMe2-7,8-C2B9H10]−

The reaction of the [(η-9-SMe₂-7,8-C₂B₉H₁₀)IrBr₂]₂ complex with Tl[Tl(η-7,8-C₂B₉H₁₁)] afforded the iridacarborane compound (η-9-SMe₂-7,8-C₂B₉H₁₀)Ir(η-7,8-C₂B₉H₁₁). The cationic complex [Cp*Ir(η-9-SMe₂-7,8-C₂B₉H₁₀)]⁺PF₆ ⁻ (5 · PF₆, Cp* is pentamethylcyclopentadienyl) was synthesized by the reaction of [Cp*IrCl₂]₂ with Na[9-SMe₂-7,8-C₂B₉H₁₀]. The structures of (η-9-SMe₂-7,8-C₂B₉H₁₀)Ir(η-cod) (cod is 1,5-cyclooctadiene) and 5 · PF₆ were established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 81–84, January, 2006.     

[CH3NH3][NH3(CH2)6NH3]H3[P2Mo2W16O62]·H2O的水热合成与表征

首次合成了[CH3NH3][NH3(CH2)6NH3]H3[P2Mo2W16O62]·H2O,通过元素分析、红外光谱和X射线单晶衍射对合成产物进行了表征,并用TGA-DSC研究了化合物的热稳定性.晶体属单斜晶系,P21/m空间群,a=1.2596(3)nm,b=1.8715(4)nm,c=1.9816(4)nm,α=γ=90°,β=90.16(3)°,V=4.671(2)nm3,Z=2,Mr=4358.66,Dc=3.100g·cm-3,μ=19.978mm-1,F(000)=3792,R=0.0835,Rw=0.2026.结果表明,在晶体结构内形成了0.7364nm×0.8354nm的微孔.