Reactions of (1,5-cyclooctadiene)duroquinonenickel with electron donors

Conclusions Electron transfer from the reducing agent to the complex occurs when the electron donors, sodionaphthalene and sodiomalonic ester, act on (1,5-cyclooctadiene)duroquinonenickel, with the formation of the [(C₈H₁₂)(DQ)Ni]^–· anion radicals, which proved to be thermally less stable and more reactive than the anion radicals of bis(duroquinone)nickel.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2320–2322, October, 1975.     

EPR study of (η5-cyclopentadienyl)nickel(I) complexes with P-and N-Donor ligands and 1,5-cyclooctadiene

Mononuclear (η⁵-cyclopentadienyl)nickel(I) complexes with triphenylphosphine, triethylphosphite, 2,2’-bipyridyl, and 1,5-cyclooctadiene formed in the course of reduction of nickelocene were studied by EPR method. Monocyclopentadienyl Ni(I) complexes of the composition CpNiL₂ were shown to form during nickelocene reduction irrespective of the method applied (the use of organometallic compound, alkali metal, thermal conditions) in the presence of stabilizing ligands L (L = PPh₃, P(OEt)₃, Bipy/2, COD/2) and in the course of contradisproportionation reaction between nickelocene and the corresponding NiL₄ complex. It was found that in the structure of these CpNiL₂ complexes (L = PPh₃, P(OEt)₃, Bipy/2), the main molecular axis is perpendicular to the L-Ni-L plane and these complexes should be considered as derivatives of trigonal structures of D _3h symmetry distorted by Cp ligand. In CpNi(COD) complex, the main axis passes through the Cpring center and this complex should be treated as a derivative of pentagonal structure of C _5v symmetry distorted by COD ligand. Nonequivalence of ³¹P nuclei results from vibronic interaction effect in tricoordinate structures in pseudodegenerate electron state (Jahn-Teller effect).     

Reactions of bis(η4-1,5-cyclooctadiene)nickel(0) with transition metal halides,and the crystal structure of μ-dichloro-bis(tetrahydrofuran)hexacarbonyldimanganese

Bis-(η⁴-1,5-cyclooctadiene)nickel(0) reacted with η⁵-C₅H₅Fe(CO)₂Cl, η³-C₅H₅Fe(CO)₃Cl, Mn(CO)₅Cl and {Mn[P(OMe)₃](CO)₄}₂ to form metal metal bonded coupling products. Partial reduction of Mn(CO)₅Cl gave [MnCl(CO)₃(THF)]₂ shown to have a chlorine-bridged C_2h structure by X-ray diffraction analysis. Ligand transfer also accompanied the reduction of Fe[P(OMe)₃]₂(CO)₂Br₂ and Fe(CO)₄Cl₂ to Fe[P(OMe)₃]₂(CO)₃ and Fe(CO)₅, respectively. Only partial reduction was observed for Ti(acac)₂Cl₂ and (η⁵-C₅H₅)₂TiCl₂ which gave [Ti(acac)₂Cl]₂ and (η⁵-C₅H₅)₂Ti(py)Cl, respectively.     

Synthesis and desilylation of some bis(trimethylsilyl)alkenes and polymers bearing bis(silyl)alkenyl groups

The synthesis of various vinylbis(silanes) from some aryl and heteroaryl aldehydes and (Me₃Si)₃CLi in Et₂O is described. Friedel-Crafts reaction of 1,1-bis(trimethylsilyl)-2-(2-naphthyl)ethene with various acyl chlorides (RCOCl, R = Me, Et, i-Pr, i-Bu, n-pent) gave the corresponding α-silyl-α,β-unsaturated enones with high E steroselectivity. Moreover, poly(styrene)-co-[2,2-bis(trimethylsilyl)ethenyl(styrene)] obtained via the reaction of polymers bearing pendant enone functions and (Me₃Si)₃CLi, reacts with the same acyl chlorides in the presence of catalytic amount of AlCl₃ to give the new macromolecules bearing α-silyl-α,β-unsaturated enones and α,β-unsaturated enones.     

Synthesis and crystal structure of bis(dimethylthioacetonedicarboxylate)nickel(II)

Summary The title compound has been synthesized and characterized. The crystal structure has been determined by single-crystal x-ray analysis from diffractometer data, and refined to R= 0.063 for 1889 observed reflections. Crystals are monoclinic, space group P2₁/n, witha=21.97(2),b=8.21(1),c=10.44(1) A, and =101.87(3), and Z=4. Both ligands are coordinated to nickel through sulphur and one oxygen atom to realize thecis form of the complex in the square planar coordination geometry. Bond distances are: Ni-S, 2.14(1), Ni-O, 1.87(1) and 1.90(1) Å. Each nickel atom also forms two close contacts with oxygen atoms from adjacent molecules.     

Crystal structure of (5-methylcyclopentadienyl)-(1,5-cyclooctadiene) iridium(I)

XRD is used to determine the structure of Cp′Ir(cod) at a temperature of 150(2) K. Crystallographic data for C₁₄H₁₉Ir are: a = 10.8272(5) ?, b = 9.7746(4) ?, c = 10.9180(5) ?, β = 97.3310(10)°, monoclinic symmetry, space group P2₁/n, V = 1146.02(9) ?³, Z = 4, d _calc= 2.199 g/cm³, R = 0.0246. The structure is molecular, built of neutral molecules. The metal atom coordinates carbon atoms of two cyclic ligands: 5-methylcyclopentadienyl-ion (Cp′) and 1,5-cyclooctadiene (cod). Five Ir-C_Cp′ distances lie in the range of 2.21–2.28 ?; four Ir-C_cod distances differ insignificantly, and their average value is 2.114(13) ?. The C₁₁C₁₂C₁₃C₁₄C₁₅ and C₁C₂C₅C₆ planes of ligand fragments are almost parallel, and the angle between normals is 1.9°. In the crystal, molecules are bonded only by van der Waals interactions; in the structure, the eight shortest Ir...Ir distances are in the range of 5.608–7.257 ?. Original Russian Text Copyright ? 2009 by K. V. Zherikova, N. B. Morozova, and I. A. Baidina __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 3, pp. 591–594, May–June, 2009.     

Synthesis and Characterization of a Bis(&mgr;-beta-diketonato)bis((1,2,5,6-eta)-1,5-dimethyl-1,5- cyclooctadiene)disilver Complex. An Intermediate in the Synthesis of an Isomerically Pure (beta-Diketonato)((1,2,5,6-eta)-1,5-dimethyl-1,5-cyclooctadiene)copper(I) Complex

Dimethyl-1,5-cyclooctadiene (DMCOD) is synthesized by the Ni-catalyzed dimerization of isoprene and consists of 80% 1,5-dimethyl-1,5-cyclooctadiene (1,5-DMCOD) and 20% 1,6-dimethyl-1,5-cyclooctadiene (1,6-DMCOD). Reaction of Hhfac (1,1,1,5,5,5-hexafluoro-2,4-pentanedione) with Ag(2)O in the presence of DMCOD results in the formation of isomeric Ag(I) species. Repeated recrystallizations yield an isomerically pure compound ((1,5-DMCOD)Ag(hfac))(2) that was characterized by X-ray crystallography and (1)H and (13)C NMR and IR spectroscopy. X-ray crystallography revealed a dinuclear complex with a short Ag-Ag spacing (3.0134(3) ? at -150 degrees C and 3.0278(5) ? at -20 degrees C) and bridging hfac ligands (&mgr;(2) bonding). The overall geometry around the Ag atoms is a deformed tetrahedron with two short Ag-O bonds (2.375 ? average) and two Ag-diene bonds. The methyl groups of the 1,5-DMCOD ligand are pointed toward the center of the molecule. Decomposition of the silver complex in a biphasic HCl (1 M)/CH(2)Cl(2) mixture liberates isomerially pure 1,5-DMCOD; this diene is subsequently used to synthesize isomerically pure (1,5-DMCOD)Cu(hfac). The latter compound was characterized by (1)H and (13)C NMR and IR spectroscopy and is a useful liquid precursor for Cu CVD. Crystallographic data: C(30)H(34)Ag(2)F(12)O(4), monoclinic, P2(1)/c (No. 14), Z = 4; at -150 degrees C, a = 12.428(1) ?, b = 11.071(1) ?, c = 24.520(2) ?, beta = 101.98(1) degrees; at -20 degrees C, a = 12.597(1) ?, b = 11.191(1) ?, c = 24.641(2) ?, beta = 102.08(1) degrees.     

Synthesis of bis(ferrocenylamino)glyoxime and its nickel(II) complex

Bis(ferrocenylamino)glyoxime has been prepared by the reaction of amino ferrocene with anti-dichloroglyoxime. The nickel(II) complex of this new compound is also described.     

Synthesis and characterization of nickel(II) bis(alkylthio)salen complexes

NiX2(2-RSC6H4CH=NCH2CH2N=CHC6H4SR-2) (NiX2L; L = 5) (1a, X = Br, R = C6H13; 1b, X = Cl, R = C12H25) and NiX2(2-C6H13SC6H4CH2NHCH2CH2NHCH2C6H4SC6H13-2) (NiX2L; L = 6) (2a, X = Br; 2b, X = Cl; 2c, X = OClO3) were prepared from ligands 5 and 6, respectively. The 1:2 metal-ligand complex Ni(OClO3)2(2-RSC6H4CH2NHCH2CH2NHCH2C6H4SR-2)2 3, was obtained from an EtOH solution of 2c. The characterization of paramagnetic 1-3 included single-crystal X-ray diffraction studies of 1a and 3. Complex 2c converted into 3 in the presence of excess ligand 6 in CHCl3.     

Structure of bis(2-methylimino-3-penten-4-onato) nickel(II). properties of nickel(II) ketoiminates

A new volatile complex Ni(mi-aa)₂ [mi-aa = CH₃C(NCH₃)CHC(O)CH₃)] is synthesized and its crystal structure is determined (APEX DUO diffractometer with a 4C CCD detector, λMoK _α, graphite monochromator, T = 100 K). Crystallographic data for Ni(mi-aa)₂ are as follows: space group Pbca, a = 5.4058(3) Å, b = 11.8684(6) Å, c = 19.8472(10) Å, V = 1273.4(1) ų, Z = 4. The Ni(II) atom is coordinated by the O and N atoms of two ligands. The Ni-O and Ni-N distances are 1.8390(9) Å and 1.926(1) Å; the chelate ONiN angle is 92.52(4)°. The complex has the molecular structure formed from the isolated molecules of Ni(mi-aa)₂ bound by van der Waals interactions. For some complexes, the TG study is performed and the intermolecular interaction energy in the crystals is calculated.     

Cycloaddition of bis(trifluoromethyl)diazomethane to activated alkenes and alkynes

Bis(Trifluoromethyl)diazomethane undergoes [3+2] cycloaddition with activated alkenes and alkynes regiospecifically to give substituted pyrazolines and pyrazoles.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 452–455, February, 1992.     

Reaction of (dichloro)(1,5-cyclooctadiene)platinum(II) with dimethyl diazomethylphosphonate. Crystal structure analysis of a bis-insertion product, (R,R)-bis[chloro(dimethoxyphosphonyl)methyl]-(1,5-cyclooctadiene)platinum(II)

The reaction of dichloro(1,5-cyclooctadiene)platinum(II), 1 with dimethyl diazomethylphosphonate, 2, results in the formation of products of insertion of the carbene moiety into one or both PtCl bonds. An X-ray diffraction study of a crystal obtained from the major bis-insertion product of this reaction shows it to be (R,R)-bis[chloro(dimethoxyphosphonyl)methylyl](1,5-cyclooetadiene)platinum(II), 5. The space group is polar indicating that spontaneous resolution has occurred upon crystallization.