Facile method for the synthesis of ruthenacarboranes, diamagnetic 3,3-[Ph2P(CH2)nPPh2]-3-H-3-Cl-closo-3,1,2-RuC2B9H11 (n = 3 or 4) and paramagnetic 3,3-[Ph2P(CH2)nPPh2]-3-Cl-closo-3,1,2-RuC2B9H11 (n = 2 or 3), as efficient initiators of controlled radical polymerization of vinyl monomers

A facile preparative procedure was developed for the synthesis of 17-and 18-electron closo-(diphosphine)ruthenacarborane complexes. This method is based on the replacement of PPh₃ ligands with bis(diphenylphosphino)alkanes Ph₂P(CH₂)_nPPh₂ (n = 2—4) in ruthenacarborane 3,3-(PPh₃)₂-3-Cl-3-H-closo-3,1,2-RuC₂B₉H₁₁. The resulting complexes exhibit high activity in controlled radical polymerization of vinyl monomers.     

The relationship between the molecular structure of [3,3-(PMe2Ph)2-closo-3,1,2-PtC2B9H11] and the mechanism of the fluxional behaviour of M(PR3)2-units in closo-twelve-atom metallaheteroboranes

The upper limit of the free energy of the barrier to rotation of the platinum bis-phosphine unit in [3,3-(PMe₂Ph)₂-closo-3,1,2-PtC₂B₉H₁₁] 1 is 30< kJ mol⁻¹ in dichloromethane solution. This relatively low value is similar in magnitude to crystal-packing forces, and compound 1 crystallises from CH₂Cl₂-hexane solution as a 1 : 1 mixture of two different conformers with significantly different platinum-to-C₂B₃ bonding. These observations lead to the proposal of a general mechanism for the mutual rotation of {M(PR₃)₂} units above C₂B₉H₁₁.     

Synthesis of 12-vertex mixed ligand closo-cobaltacarborane complexes and molecular structure of [3,3-(Ph2P(CH2)2PPh2)-3-Cl-closo-3,1,2-CoC2B9H11]

A reaction of complexes CoCl₂(dppe) (dppe is the 1,2-bis(diphenylphosphino)ethane) or CoCl₂(dppp) (dppp is the 1,3-bis(diphenylphosphino)propane) with [K][7,8-nido-C₂B₉H₁₂] upon reflux in benzene led to the mixed ligand closo-cobaltacarboranes [3,3-(Ph₂P(CH₂) _n PPh₂)-3-Cl-closo-3,1,2-Co^IIIC₂B₉H₁₁] (n = 2 and 3, respectively) in moderate yields (34 and 16%). The structure of the 18-electron complexes in solution and the solid state was studied by NMR and IR spectroscopy, the structure in the case of the closo-complex with dppe-ligand was confirmed by X-ray crystallography.     

Synthesis and the structure of the triphenylphosphine complex of o-nickelacarborane, 3,3-(PPh3)2-3,1,2-NiC2B9H11

The reaction of bis(o-dicarbollyl)nickel(iv) with PPh₃ in EtOH gave rise to the complex 3,3-(PPh₃)₂-3,1,2-NiC₂B₉H₁₁ (2) whose structure was established by X-ray diffraction analysis.     

Formation of bridging alkene and conjugated dialkenes exclusively generated from alkynes on the [3,3'-Co(1,2-C2B9H11)2]- platform. The unique hydroboration role of [3,3'-Co(1,2-C2B9H11)2]-

The unprecedented metal-mediated transformation of an alkyne into a B,B' bridging alkene is reported. Also, the unprecedented synthesis of a conjugated dialkene derivative of [3,3'-Co(1,2-C2B9H11)2]- generated only from an alkyne, contrary to the usual case where an alkyne and an alkene are needed, is described. This has been possible through the singular capacity of a B-H to produce hydroboration.     

Solvothermal Synthesis and Crystal Structure of [H2N（CH2）2NH3]{Co[H2N（CH2）2NH2]3}[SbSe4]

1 INTRODUCTION The chalcogenidometallates with open frame- works have attracted considerable interest as pos- sible zeolite-like materials, of which highly interes- ting properties could be expected. Over the last de- cades a large number of thioanti…     

Darstellung, 11B-NMR-, Schwingungsspektren und Kristallstruktur von [(C5H5N)2CH2][1-(O2N)B10H9]

Preparation, ¹¹B NMR, Vibrational Spectra, and Crystal Structure of [(C₅H₅N)₂CH₂][1-(O₂N)B₁₀H₉] By reaction of [B₁₀H₁₀]^2? in aqueous acetonitrile with a saturated solution of NO₂ in dichloromethane [1-(O₂N) · B₁₀H₉]^2? and [B₁₀H₉(NO)B₁₀H₉]^3? are formed which can be separated by ion exchange chromatography on diethylaminoethyl(DEAE) cellulose from the starting compound. The X-ray structure determination of [(C₅H₅N)₂CH₂][1-(O₂N)B₁₀H₉] (triclinic, space group P1 , a = 7.1530(9), b = 8.3753(8), c = 15.198(2) Å, α = 96.00(1), β = 95.48(1), γ = 95.60(1)°, Z = 2) reveals the coordination of the NO₂ group via N with a B1? N distance of 1.535(5) Å and an O2? N? O1 angle of 119.3(3)°. The ¹¹B NMR spectrum exhibits the characteristic feature (1 : 1 : 4 : 4) of an apical monosubstituted B₁₀ cluster with a strong downfield shift of the ipso-B atom at +13.4 ppm. The IR and Raman spectra show strong NO stretching vibrations at 1381 und 1420 cm^?1.     

Undecaborates M2[B11H11]: Facile Synthesis,Crystal Structure,and Reactions

closo-Undecaborates were synthesized by the deprotonation of B₁₁H₁₃(SMe₂) with LitBu in thp or K[BHEt₃] in thf, [Li(thp)₃]₂[B₁₁H₁₁] and K₂[B₁₁H₁₁] being obtained in 83 and 93% yield, respectively. K₂[B₁₁H₁₁] can be transformed into A₂[B₁₁H₁₁] with the corresponding ammonium chlorides in aqueous solution (A = [NMe₃Ph], [NBzlEt₃], [N(PPh₃)₂]). The crystal structure analysis of [Li(thp)₃]₂[B₁₁H₁₁] (space group P2₁/c) reveals a rather distorted octadecahedron for the [B₁₁H₁₁]^2– anion, whereas the corresponding octadecahedron in [NBzlEt₃]₂[B₁₁H₁₁] (space group P2₁2₁2₁) exhibits a structure close to C_2v symmetry, expected for the free anion. The protonation of [B₁₁H₁₁]^2– at low temperature gives [B₁₁H₁₂]^–, whose structure could be elucidated by NMR methods; it is formed, apparently, by the opening of the B1–B4 edge of [B₁₁H₁₁]^2– in the course of its known degenerate skeletal rearrangement, followed by the protonation of the B2–B4 edge. The reaction of [B₁₁H₁₂]^– with a second molecule of the acid HX (X = CF₃COO) gives nido-[B₁₁H₁₃X]^–. The addition of BH₃ to [B₁₁H₁₁]^2– yields closo-[B₁₂H₁₂]^2– under loss of H₂. Two [B₁₁H₁₁]^2– units are fused by the aid of FeCl₃, with the known anion [B₂₂H₂₂]^2– as the product, whose ¹¹B-NMR signals could completely be assigned on the basis of C_s symmetry. The compound [NBzlEt₃][N(PPh₃)₂][B₂₂H₂₂] crystallizes in the space group Pna2₁.     

Sterically-induced low temperatur polyhedral rearrangements of carbaplatinaboranes: Synthesis and crystal structures of 1-Ph-3,3-(PMe2Ph)2-3,1,2-PtC2B9H10, 1-Ph-3,3-(PMe2Ph)2-3,1,11-PtC2B9H10, 11-Ph-3,3-(PMe2Ph)2-3,1,11-PtC2B9H10 and 1,11-Ph2-3,3-(PMe2Ph)2-3,1,11-PtC2B9H9

Reaction of cis-Pt(PMe₂Ph)₂Cl₂ with Tl₂[7-Ph-7,8-nido-C₂B₉H₁₀] affords 1-Ph-3,3-(PMe₂Ph)₂-3,1,2-PtC₂B₉H₁₀, mild thermolysis (55°C) of which yields 1-Ph-3,3-(PMe₂Ph)₂-3,1,11-PtC₂B₉H₁₀ and 11-Ph-3,3-(PMe₂Ph)₂-3,1,11-PtC₂B₉H₁₀. Both of the latter compounds are produced by the microwave irradiation of a mixture of cis-Pt(PMe₂Ph)₂Cl₂ and [HNMe₃][7-Ph-7,8-nido-C₂B₉H₁₁]. When cis-Pt(PMe₂Ph)₂Cl₂ is allowed to react with Tl₂[7,8-Ph₂-7,8-nido-C₂B₉H₉] at room temperature the only isolable species is 1,11-Ph₂-3,3-(PMe₂Ph)₂-3,1,11-PtC₂B₉H₉. The generation of rearranged products with 3,1,11-PtC₂B₉ architectures is inconsistent with a diamond-square-diamond mechanism for the isomerisation of icosahedral heteroboranes.     

Syntheses,Crystal Structures and Properties of Three New Complexes [Ni（C9N2O2H7）2（CH3OH）2],[Zn（C9N2O2H7）2（H2O）2] and [Cd（C9N2O2H7）2（CH3OH）2]

Three novel metal-organic complexes with formulas [Ni(C9N2O2H7)2(CH3OH)2](1),[Zn(C9N2O2H7)2(H2O)2](2) and [Cd(C9N2O2H7)2(CH3OH)2](3) were synthesized by the reactions of Ni,Zn and Cd salts with ethyl 2-benzimidazolylacetate under hydrothermal conditions or layering technique,and characterized by single-crystal X-ray diffraction analysis,IR spec-troscopy,solid-state luminescent properties and thermogravimetric(TG) analysis.The crystal data for these three complexes are as follows:for 1,monoclinic,space group P21/c,a = 9.384(3),b = 9.634(3),c = 11.292(3) ,β = 95.787(5)°,V = 1015.7(5) 3,Z = 2,F(000) = 492,Dc = 1.547 Kg/m3,μ = 1.002 mm-1,the final R = 0.0451 and wR = 0.0900 for 1833 observed reflections with Ⅰ 2σ(Ⅰ);for 2,orthorhombic,space group Pbca,a = 10.031(4),b = 10.379(4),c = 17.525(7),V = 1824.6(12) 3,Z = 4,F(000) = 928,Dc = 1.645 Kg/m3,μ = 1.392 mm-1,the final R = 0.0452 and wR = 0.0996 for 1661 observed reflections with Ⅰ 2σ(Ⅰ);for 3,monoclinic,space group P21/c,a = 9.9114(13),b =10.4852(15),c = 10.4120(14) ,β = 108.453(5)°,V = 1026.4(2) 3,Z = 2,F(000) = 532,Dc = 1.705 Kg/m3,μ = 1.110 mm-1,the final R = 0.0322 and wR = 0.0805 for 1822 observed reflections with Ⅰ 2σ(Ⅰ).In the three complexes,the ethyl 2-benzimidazolylacetate shows the same chelating mode,and the adjacent units are interlinked into a two-dimensional layer through hydrogen-bonds(O-H···O,N-H···O).     

Synthesis and characterization of novel chelated dimethylamino lithium alkoxides: molecular structures of [1‐LiOC(C6H11)2‐2‐NMe2C6H4]2 and [1‐LiOCPh2CH2‐2‐NMe2C6H4]2

From the reaction of 1‐HOCPh₂‐2‐NMe₂C₆H₄ ( 1 ), 1‐HOC(C₆H₁₁)₂‐2‐NMe₂C₆H₄ ( 2 ) and 1‐HOCPh₂CH₂‐2‐NMe₂C₆H₄ ( 3 ) with n‐BuLi in diethyl ether, the solvent‐free chelated dimethylamino lithium alkoxides [1‐LiOCPh₂‐2‐NMe₂C₆H₄]₂ ( 4 ), [1‐LiOC(C₆H₁₁)₂‐2‐NMe₂C₆H₄]₂ ( 5 ) and [1‐LiOCPh₂CH₂‐2‐NMe₂C₆H₄]₂ ( 6 ) were obtained. The lithium alkoxides 4 – 6 were characterized by ¹H, ⁷Li, and ¹³C NMR spectroscopy. Crystal structure determinations of 5 and 6 were carried out. Compounds 5 and 6 are examples of structurally characterized solvent‐free chelated dimethylamino lithium alkoxides and 6 is a rare example of this type containing a seven‐membered ring. Copyright © 2002 John Wiley & Sons, Ltd.     

Synthesis and characterization of arsacycloalkanes and their palladium and platinum complexes,and X‐ray structure of [PdCl2(PhAsCH2CH2CH2CH2CH2)2]

Reactions of PhAsCl₂ with BrMg(CH₂)_nMgBr (n = 4 or 5) in THF gave phenylarsacycloalkanes as colourless oily liquids which could be distilled under vacuum. Treatment of PhAs(CH₂)_n­with MCl₂(RCN)₂ (M = Pd or Pt; R = Ph­or Me) afforded mononuclear complexes, [MCl₂{PhAs(CH₂)_n}₂]. Reactions with [Pt₂Cl₂(μ‐Cl)₂(PEt₃)₂] gave mixed‐ligand complexes, [PtCl₂(PEt₃){PhAs(CH₂)_n]. The palladium complexes adopt a trans geometry whereas the platinum complexes exist in a cis configuration. The crystal and molecular structure of [PdCl₂(PhAsCH₂CH₂CH₂CH₂CH₂)₂] was determined by X‐ray diffraction methods. The molecule consists of a square‐planar palladium atom with trans chlorides and trans arsa ligands. The six‐membered ‘AsC₅′ ring adopts a chair conformation. Copyright © 1999 John Wiley & Sons, Ltd.     

Dual fluorescence from an isonido ReIII rhenacarborane phosphine complex, [7,10-mu-H-7-CO-7,7-(PPh3)2-isonido-7,8,9-ReC2B7H9

The complex [7,10-mu-H-7-CO-7,7-(PPh3)2-isonido-7,8,9-ReC2B7H9] has been synthesized by treatment of the complex salt [NHMe3][3,3-Cl2-3,3-(CO)2-closo-3,1,2-ReC2B9H11] with PPh3 in refluxing THF (tetrahydrofuran) and isolated as intensely colored orange-red microcrystals. Spectroscopic NMR and IR data have suggested that the product has a highly asymmetric structure with two inequivalent PPh3 ligands and a single CO ligand. Measurement of 11B NMR spectra in particular have indicated seven distinct boron vertexes, although the resulting cage degradation by removal of two BH vertexes was confirmed only following X-ray crystallographic analysis, which revealed the pentadecahedral isonido-7,8,9-ReC2B7 architecture. The 11B NMR resonances span an enormous chemical shift range (Deltadelta = 113), and this appears to be a direct consequence of the deshielding of the boron vertex directly opposite the quadrilateral |ReCCB| aperture. The new complex has been shown by electrochemical measurements to undergo a reversible one-electron oxidation. Digitally simulated cyclic voltammograms support a proposed square scheme (E(1/2) = 0.58, 0.69 V vs ferrocene) involving a reversible isonido-closo transition of the metallacarborane cage. Most unusually for a metallacarborane complex, ambient temperature solutions in CH2Cl2 and DMF have been shown to be intensely turquoise-blue fluorescent (lambda(em) = 442 nm, Phi = 0.012). Fluorescence spectroscopy measurements in MeTHF (2-methyltetrahydrofuran) glass at 77 K have indicated that the likely cause of such a broad emission is dual fluorescence (lambda(em) = 404, 505 nm), with both emissions displaying vibronic structure. Following excited-state lifetime decay analysis, the emissive behavior has been accredited to metal-perturbed 1IL states, with the lower energy emission arising from a slight geometric distortion of the initially excited complex.     

Intramolecular reduction of the nitro group into phosphoraneimine mediated by a rhenium(v) complex. Synthesis and structure of the novel phosphoraneimine oxorhenium(v) complex [ReOCl[o-(PPh3=N)C6H4(NCH2CH2N(CH2CO2H)CH2CO2]

The title compound was synthesised via an unexpected intramolecular reduction of a nitro group in the oxo-Re(v) coordination sphere.     

Synthesis, structure, and dynamics of nickelacarboranes incorporating the [nido-7,9-C(2)B(9)H(11)](2)(-) ligand

The nickelacarboranes [NEt(4)][2-(eta(3)-C(3)H(4)R)-closo-2,1,7-NiC(2)B(9)H(11)] (R = H (1a), Ph (1b)) have been synthesized via reaction between [Na](2)[nido-7,9-C(2)B(9)H(11)] and [Ni(2)(micro-Br)(2)(eta(3)-C(3)H(4)R)(2)] in THF (THF = tetrahydrofuran), followed by addition of [NEt(4)]Cl. Protonation of 1a in the presence of a donor ligand L affords the complexes [2,2-L(2)-closo-2,1,7-NiC(2)B(9)H(11)] (L = CO (2), CNBu(t) (3)). Addition of PEt(3) (1 equiv) to 2 produces quantitative conversion to [2-CO-2-PEt(3)-closo-2,1,7-NiC(2)B(9)H(11)], 4. Species 2-4 exhibit in solution hindered rotation of the NiL(2) fragment with respect to the eta(5)-C(2)B(9) cage unit. Protonation of 1a in the presence of a diene affords the neutral complexes [2-(eta(2):eta(2)-diene)-closo-2,1,7-NiC(2)B(9)H(11)] (diene = C(5)Me(5)H (5), dcp (6), cod (7), nbd (8), chd (9), and cot (10a); dcp = dicyclopentadiene, cod = 1,5-cyclooctadiene, nbd = norbornadiene, chd = 1,3-cyclohexadiene, and cot = cyclooctatetraene). Variable temperature (1)H NMR experiments show that the [Ni(diene)] fragments are freely rotating even at 193 K. A small quantity of the di-cage species [2,2'-micro-(1,2:5,6-eta-3,4:7,8-eta-cot)-(closo-2,1,7-NiC(2)B(9)H(11))(2)] (10b) is formed as a coproduct in the synthesis of 10a. This species can be rationally synthesized by protonation of 1a and subsequent addition of 10a.     

Yttrium complexes incorporating the chelating diamides [ArN(CH2)xNAr]2- (Ar = C6H3-2,6-iPr2, x= 2, 3) and their unusual reaction with phenylsilane

Novel yttrium chelating diamide complexes [(Y[ArN(CH(2))(x)NAr](Z)(THF)(n))(y)] (Z = I, CH(SiMe(3))(2), CH(2)Ph, H, N(SiMe(3))(2), OC(6)H(3)-2,6-(t)Bu(2)-4-Me; x = 2, 3; n = 1 or 2; y = 1 or 2) were made via salt metathesis of the potassium diamides (x = 3 (3), x = 2 (4)) and yttrium triiodide in THF (5,10), followed by salt metathesis with the appropriate potassium salt (6-9, 11-13, 15) and further reaction with molecular hydrogen (14). 6 and 11(Z = CH(SiMe(3))(2), x = 2, 3) underwent unprecedented exchange of yttrium for silicon on reaction with phenylsilane to yield (Si[ArN(CH(2))(x)NAr]PhH) (x = 2 (16), 3) and (Si[CH(SiMe(3))(2)]PhH(2)).     

The crystal and molecular structure of cesium 9,10,11-trimethyl-7,8-dicarba-nido-undecaborate(1-) Cs[9,10,11-Me3-7,8-C2B9H9]

Conclusions By a complete x-ray diffraction study of cesium 9,10,11-trimethyl-7,8-dicarba-nido-undecaborate(1-) we proved the axial orientation of the Me group attached to the B¹⁰ atom of the open face of the nido-carborane polyhedron. This serves as an additional proof of the stereospecificity of the alkylation reaction of the dicarbollide ions and the necessity for a migration stage of the boron atom with the substituent to the site of the deficient apex of the icosahedron to form a derivative with an equatorial disposition of the alkyl group.The atoms in the carborane polyhedron are numbered as in [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2474–2481, November, 1979.     

Synthesis of monohalogeno derivatives of closo-[B9H9]2-. Crystal structures of (Ph4P)2[1-XB9H8].CH3CN (X = Cl, Br, I)

By reaction of Na2[B9H9] with the appropriate N-halogenosuccinimide, the monohalogenated anion [1-XB9H8]2- (X = Cl, Br, or I) is formed. The X-ray diffraction analyses performed on single crystals of (Ph4P)2[1-XB9H8].CH3CN (X = Cl, Br, I) reveal that the tricapped trigonal prismatic geometry of the cluster is retained after substitution in the 1-position. Crystallographic data are as follows for (Ph4P)2[1-XB9H8].CH3CN. X = Cl, Br: monoclinic, space group P2(1), a = 10.7 A, b = 32.9 A, c = 13.8 A, beta = 96 degrees, Z = 4, R1 = 0.038 and R1 = 0.036, respectively. X = I: monoclinic, space group P2(1)/n, a = 10.5 A, b = 13.6 A, c = 33.4 A, beta = 94 degrees, Z = 4, R1 = 0.094. The compounds have been characterized by vibrational and 11B NMR spectroscopy as well.