V. P. Dyadchenko

Syntheses of organogold(1+) compounds by direct auration

Abstract Organogold(1+) compounds have been synthesized by direct auration of cyclopentadiene, cyanoacetic ester and malonitrile with (Ph 3 PAu) 3 O + BF 4 − . An X-ray structural study (λ Mo, 5062 reflections, R = 0.039) of bis(triphenylphosphinegold)malonitrile has been carried out (monoclinic, a = 12.055(6), b = 14.086(5), c = 20.466(12) A, β = 90.32(4)°, space group P 2 1 / c , Z = 4). The AuAu bond length is 2.912(1) A.

New organogold complexes: tetraphenylcyclopentadiene derivatives

Abstract Mono- and diaurated derivatives of tetraphenylcyclopentadiene, Ph4C5HAu-PPh3 and Ph4C5(AuPPh3)2, have been obtained by auration of tetraphenylcyclopentadiene with tris(triphenylphophinegold)oxonium tetrafluoroborate. Under the action of [Ph3,PAu]+BF4− both mono- and diaurated derivatives form the trinuclear cationic complex [Ph4C5(AuPPh3)3]+BF4−, which is converted into Ph4C5(AuPPh3)2 when treated with nucleophiles. The structure of Ph4C5HAuPPh3 and [Ph4C5(AuPPh3)3]+BF4− was established by IR, UV, PMR spectral and X-ray structural studies. Ph4C5HAuPPh3 has a CAu bond and additional coordination of Au with two neighboring carbon atoms of the five-membered ring; the structure is non-fluxional. The complex [Ph4C5(AuPPh3)3]+BF4− includes rather rare structural moieties: a three-membered carbometal cycle AuCAu , three gold atoms linked to each other, AuAuAu, and univalent gold coordinated with three carbon atoms of the Ph4C5 ring.

Synthesis and structure of tris(4-ferrocenylphenyl)boroxine and its utility in cross-coupling reaction

The reaction of 4-bromophenylferrocene with butyllithium followed by treatment of the organolithium compound with tributyl borate afforded tris(4-ferrocenylphenyl)boroxine (2). X-ray diffraction study of the solvate 2·2C6H6 revealed an intermolecular stacking interaction between the boroxine ring and the Cp rings in the crystal structure. Cross-coupling of compound 2 with 4’-bromo-4-nitro-1,1’-biphenyl produced 4″-ferrocenyl-4-nitro-1,1’:4’,1″-terphenyl (3). X-ray diffraction study of terphenyl 3 showed that this compound crystallizes in the noncentrosymmetric space group P21. In the crystal, molecules 3 are packed in an antiparallel head-to-tail fashion, which is unfavorable for generation of strong nonlinear optical effects.

Thermotropic liquid crystals based on ferrocenylbiphenyl and ferrocenylterphenyl

4′‐Ferrocenyl‐1,1′‐biphenyl‐4‐yl 4‐alkoxybenzoates Fc–(C6H4)2–OC(O)–C6H4–O–C n H2n+1 (n = 8, 10, 12) (3a–c), representing a new class of ferrocene‐containing thermotropic mesogens with nematogenic properties, were prepared. Two approaches were used for the construction of these mesogens: (i) reaction of 4′‐ferrocenyl‐1,1′‐biphenyl‐4‐ol with 4‐alkoxybenzoylchlorides, and (ii) crosscoupling of tris(4‐ferrocenylphenyl)boroxine with the corresponding halobenzenes. Crosscoupling was also applied for the synthesis of terphenyl‐containing mesogens Fc–(C6H4)3–OC(O)–C6H4–O–C n H2n+1 (n = 10, 12) (6a,b) and (RC5H4)Fe‐[C5H4–(C6H4)3–OC(O)–C6H4–O–C10H21] (11a, R = Et; 11b, R = n−Bu). The latter compounds also form nematic phases. Mesogens 6a,b form mesophases with wider temperature ranges than their biphenyl‐containing counterparts 3b,c. The most pronounced mesomorphism was displayed by compounds 11a and 11b, which have mesophases in the ranges 141–253°C and 120–238°C, respectively. The purity of compounds was established by 1H NMR spectra and elemental analysis. Mesophases were identified by polarizing optical microscopy and differential scanning calorimetry.

Compounds of hypercoordinated gold(i)

A binuclear organic derivative of gold(i) with diphenylmethane CH2(C6H4)2(AuPPh3)2 has been prepared by the reaction of 2,2′-dilithiumdiphenylmethane with ClAuPPh3. X-ray analysis of this compound revealed a transoid conformation of the molecule with agostic bonds between the gold atoms and methylene hydrogens. The complex was characterized by IR,1H and31P NMR, and mass spectral data.

Cyanomethyl derivatives of gold

Conclusions1.Triphenylphosphine complexes of cyanomethylgold and dichlorocyanomethylgold have been synthesized.2.The chemical properties of aurated acetonitrile were typical for σ organogold compounds but aurated dichloroacetonitrile recalled the chemical behavior of complex gold halides3.The gold atom in the molecule of dichlorocyanomethyl (triphenylphosphine) gold has linear coordination, the bond lengths and angles were typical for organic complexes of univalent gold.

Auration of ferrocene and its derivatives

Conclusions1.Ferrocene and its derivatives are aurated by the tris(triphenylphosphinegold) oxonium salt.2.A series of ferrocene cationic organogold complexes are obtained.3.Auration of ferrocene derivatives occurs primarily in position 2 both with donor and with acceptor substituents.

Ferrocenylbiphenylyl- and ferrocenylterphenylyl-containing liquid crystals: Solid-phase precursors, structure, and properties

This paper reports on the results of investigations into the liquid-crystal properties and structure of compounds belonging to a new class of mesogens containing monosubstituted ferrocenyl fragments, such as 4′-ferrocenyl-1,1′-biphenyl- and (terphenyl)-4-yl 4-alkoxybenzoates of the general formula Fc-(C6H4)m-O2C-C6H4-O-CnH2n+1 (m = 2, 3; n = 6, 8, 10, 12) and 4-alkoxyphenyl 4′-ferrocenyl-1,1′-biphenylyl-4-carboxylates of the general formula Fc-(C6H4)2-CO2-C6H4-O-CnH2n+1 (n = 10, 12). The crystal packings of the ferrocene-containing mesogens are theoretically predicted and calculated, and the results obtained are discussed.

4-Ferrocenyl-2-fluorophenylboronic acid: synthesis and structure

Abstract4-Ferrocenyl-2-fluorophenylboronic acid was obtained from ferrocene in two steps. In crystal, this compound forms a dimer due to the O–H...O hydrogen bonds and exhibits a stacking-interaction between benzene rings (∼3.47 Å), combining the dimers in chains.

Interaction of organogold(I) compounds with tetraalkylthiuram disulfides

Abstract Reactions of tetraalkylthiuram disulfides with RAuPPh 3 complexes (R = alkyl, phenyl, ferrocenyl) lead by oxidation to gold(III) dialkyldithiocarbamates. The products formed gaves satisfactory elemental analysis.