Synthesis and structural characterization of symmetrical closo-4,7-I2-1,2-C2B10H10 and [(CH3)3NH][nido-2,4-I2-7,8-C2B9H10

The boron-atom insertion reaction of nido-9,11-I(2)-7,8-C(2)B(9)H(9)(2-), with the HBCl(2):SMe(2) complex yields closo-4,7-I(2)-1,2-C(2)B(10)H(10), 1, in excellent yield. Although the two boron atoms (B3 and B6) nearest to the carbon atoms in 1 are equally available for attack by nucleophiles, the boron-degradation reaction of 1 with alkoxide ion occurs only at the B6 vertex, yielding regioselectively [(CH(3))(3)NH][nido-2,4-I(2)-7,8-C(2)B(9)H(10)], 2. The molecular structures of 1 and 2 have been determined by X-ray diffraction studies. Crystallographic data are as follows. For 1, monoclinic, space group P2(1)/n, a = 6.9199(19) Angstroms, b = 23.9560(7) Angstroms, c = 7.2870(2) Angstroms, beta = 94.081(4) degrees, V = 1204.9(6) Angstroms(3), Z = 4, rho(calcd) = 2.18 g cm(-3), R = 0.020, R(w) = 0.0610; for 2, orthorhombic, space group Pca2(1), a = 14.1141(7) Angstroms, b = 7.0276(4) Angstroms, c = 16.4602(9) Angstroms, V = 1632.7(15) Angstroms(3), Z = 4, rho(calcd) = 1.81 gcm(-3), R = 0.022, R(w) = 0.0623.     

Synthesis and structure of the new binuclear complex η5-C5H5(CO)2Fe-η1-C5H4(CO)2Fe-CH3

Conclusions The new binuclear complex ⁵-C₅H₅(CO)₂Fe-¹-C₅H₄(CO)₂Fe-CH₃ was synthesized. Its structure was established by x-ray crystallographic analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 437–440, February, 1986.     

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 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].     

新型1-吡啶基-3,5-二甲基-1-氢吡唑类化合物的合成及晶体结构

以卤代吡啶为起始原料与水合肼反应合成肼基吡啶衍生物中间体,该中间体进一步与2,4-戊二酮关环合成了一类新型1-吡啶基-3,5-二甲基吡唑衍生物。对合成目标化合物进行了质谱、核磁表征。并且采用X射线单晶衍射分析方法进一步测定了目标化合物1-(3,5,6-三氯吡啶-2-基)-3,5-二甲基-1氢吡唑(3f)的晶体结构。     

Theoretical study of isoelectronic molecules: B6H10, 2-CB5H9, 2,3-C2B4H8, 2,3,4-C3B3H7, and 2,3,4,5-C4B2H6

Isoelectronic molecules regarding B6H10, 2-CB5H9, 2,3-C2B4H8, 2,3,4-C3B3H7, and 2,3,4,5-C4B2H6 are studied by the density functional B3LYP/6-311G(d,p) method and the electron propagator theory in the partial third-order quasiparticale approximation, as well as the extrapolated calculation with the coupled-cluster CCSD(T) theory. The calculated ionization potentials are in good agreement with the experimental data from photoelectron spectroscopy. Valence structures are characterized with natural orbital bond (NBO) theory, exhibiting the multiple three-center two-electron bonds B-H-B, B-B-B, C-B-B, B-C-B, and C-B-C, and chemical bond rearrangements in the cations.     

2-氨基-3-羟基环戊烯-1-腈衍生物的合成和晶体结构

用低价钛试剂(TiCl~4-Zn)与α,α-(4-氯苯基)(二氰甲基)甲基苯基酮反应合成了非对映消旋体(3R,5S;3S,5R)和(3R,5R;3S,5S)2-氨基-3-羟基-3-苯基-5-对氯苯基环戊烯-1-腈。并用X射线衍射分析确定了这两个非对映异构体的构型。     

Molecular and crystal structure of nido-9-C5H5N-11-I-7, 8-C2B9H10: Supramolecular architecture based on hydrogen bonds X-H⋯I (X = B, C)

A single crystal X-ray diffraction study of a new iodine-containing cluster compound 9-(pyridine)-11-iodo-decahydro-7,8-dicarba-nido-undecaborane [9-C₅H₅N-11-I-7,8-C₂B₉H₁₀] has been performed. Crystal data: C₇H₁₅B₉NI, M = 337.39, monoclinic, space group P2₁/c, unit cell parameters: a = 9.348(1) Å, b = 11.159(1) Å, c = 13.442(2) Å, β = 98.13(1)°, V = 1388.1(5) ų, Z = 4, d _calc = 1.614 g/cm³, T = 295 K, F(000) = 648, μ = 2.276 mm^?1. The structure was solved by a direct method and refined in the full-matrix anisotropic approximation (isotropic for hydrogen atoms) to final agreement factors R ₁ = 0.0254, wR ₂ = 0.0454 for 2437 I _hkl ≥ 2σ_I from 3590 measured I _hkl (an Enraf-Nonius CAD-4 diffractometer, λMoK _α , graphite monochromator, θ/2θ-scanning). The molecules are joined into a supramolecular assembly by hydrogen bonds X-H?I (X = B, C).     

3-氯-4-二苄胺基-5-甲氧基-2(5H)-呋喃酮的合成与晶体结构

在THF溶液中合成了标题化合物3-氯-4-二苄胺基-5-甲氧基-2(5H)-呋喃酮,并用FT-IR、UV-Vis、1HNMR、13C NMR、MS、元素分析和X-射线衍射等进行了表征。结果表明此化合物属正交晶系,空间群为Pbca,晶胞参数为:a=15.891(16),b=11.126(11),c=19.778(19),α=β=γ=90°,V=3497(6)3,Z=8,Dc=1.306Mg/m3,μ=0.234 mm-1,F(000)=1440。在化合物的分子结构中,两个苯环几乎垂直于呋喃酮平面,且它们与呋喃酮平面的两面角分别为89.38°和88.19°。     

Synthesis, spectroscopic properties and crystal structure determination of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole derivatives

Substituted 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole derivatives 2, 3 and 6 were synthesized. 2-(2-Pyridin-4-yl-vinyl)-1H-benzimidazole 2 and 6-methyl-2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 3 were prepared by condensation reaction from 3-pyridin-4-yl-acrylic acid and corresponding 1,2-phenylenediamines in polyphosporic acid (PPA). 2,7,11-b-Triaza-benzo[c]fluorene 4 was prepared by photochemical dehydrocyclization reaction of ethanolic solution of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 2. 2-(2-Pyridin-4-yl-vinyl)-3H-benzimidazole-6-carbonitrile 6 was prepared by condensation reaction from 3-pyridin-4-yl-propenal and 4-cyano-1,2-phenylenediamine using p-benzoquinone as oxidants. The structure of novel benzimidazole derivatives has been studied by ¹H and ¹³C NMR, IR, MS, UV/Vis and fluorescence spectroscopy. The structure of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 2 was confirmed by X-ray single crystal structure analysis. The conformation of the molecule is E in regard to substituents position around vinyl double C=C bond. The non-planar molecules are mutually connected via the N–H···N and C–H···N type of intermolecular hydrogen bonds into infinite chains spreading along y axis.     

Synthesis and crystal structure of (Et4N)[{μ 3-SbI}Fe3(η 5-C5H5)(CO)10]

Crystal structure of (Et₄N)[{μ ₃-SbI}Fe₃-SbI}Fe₃Cp(CO)₁₀] was determined by X-ray diffraction analysis. The compound was synthesized by the reaction between (Et₄N)₂[Fe₂(CO)₈] and CpFe(CO)₂SbI₂ in a THF solution with cooling in an argon atmosphere. The crystals are monoclinic, a=12.792(2), b=14.152(3), c=17.373(3) Å, β=92.32(1)°, V_cell=3143(1) ų, space group P2₁/n, Z=4, d_calc=1.885 g/cm³, Syntex P2₁, λCuK_α radiation, R(F)=0.0744 for 877 F_hkl>6σ(F_hkl). The data were corrected for crystal decomposition according to the drop in the intensities of control reflections (by 23% during 29 h X-ray exposure). In the cluster anion, the Sb?Fe distances (ave. 2.57(1) Å) and the I?Sb?Fe and Fe?Sb?Fe angles (ave. 102.7(6) and 115.4(4)°) have virtually the same values as in other known complexes containing HalSbFe₃ and SbFe₄ fragments. The Fe...Fe distances of 4.312-4.369 Å indicate that the metal-metal bonds are absent.     

Metallaboranes of the Early Transition Metals: Direct Synthesis and Characterization of [{(eta5-C5Me5)Ta}2BnHm] (n=4, m=10; n=5, m=11), [{(eta5-C5Me5)Ta}2B5H10(C6H4CH3)], and [{(eta5-C5Me5)TaCl}2B5H11

Reaction of [Cp*TaCl4] (Cp*=eta5-C5Me5) with a sixfold excess of LiBH(4)thf followed by BH3thf in toluene at 100 degrees C led to the isolation of hydrogen-rich metallaboranes [(Cp*Ta)2B4H10] (1), [(Cp*Ta)2B5H11] (2), [(Cp*Ta)2B5H10(C6H4CH3)] (3), and [(Cp*TaCl)2B5H11] (4) in modest yield. Compounds 1-3 are air- and moisture-sensitive but 4 is reasonably stable in air. Their structures are predicted by the electron-counting rules to be a bicapped tetrahedron (1), bicapped trigonal bipyramids (2, 3), and a nido structure based on a closo dodecahedron 4. Yellow tantalaborane 1 has a nido geometry with C2v symmetry and is isostructural with [(Cp*M)2B4H8] (M=Cr and Re); whereas 2 and 3 are C3v-symmetric and isostructural with [(Cp*M)2B5H9] (M=Cr, Mo, W) and [(Cp*ReH)2B5Cl5]. The most remarkable feature of 4 is the presence of a hydride ligand bridging the ditantalum center to form a symmetrical tantalaborane cluster with a long Ta--Ta bond (3.22 A). Cluster 4 is a rare example of electronically unsaturated metallaborane containing four TaHB bonds. All these new metallaboranes have been characterized by mass spectrometry, 1H, 11B, and 13C NMR spectroscopy, and elemental analysis, and the structural types were unequivocally established by crystallographic analysis of 1-4.     

Synthesis of some 3-alkenyl-4-oxo-1-phenyl-5,6-dihydro-1H,4H, -pyrano[2,3-C]pyrazole derivatives

The title compounds were prepared from 3-alkenyl-1-phenyl-2-pyrazolin-5-one derivatives and α,β-unsaturated acyl chlorides as potential cardiotonic agents.     

Localization of mos and electronic populations in closo-carboranes 1,5-C2B3H5 and 1,6-C2B4H6

We have analyzed the electronic populations of chemical bonds and atoms in the highly symmetric closo-carboranes 1,5-C₂B₃H₅ (I) and 1,6-C₂B₄H₆ (II). The overlap populations _XY are compared with the corresponding Mulliken indices. We note substantial nonadditivity of the populations XY for closed three-center bonds BCB' and the closeness of the total overlap population _t to its maximum value. We have established the localization of the natural MOs on the bonds CH, BH, and BCB', and for molecule I also on the CBC' bonds. The effects of conjugation of bonds in the closo-carborane polyhedron are apparent in the linear dependence of these MOs. The corresponding nonorthogonal hybrid AOs of carbon and boron are also linearly dependent. We have formulated the concept of unshared population of an atom.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 4, pp. 451–456, July–August 1987.