Synthesis and structure of tris(4-N,N-dimethylaminophenyl)antimony(V) difluoride, dichloride, and dibenzoate

tris(4-N,N-Dimethylaminophenyl)antimony dichloride (I) was prepared by the reaction of tris(4-N,N-dimethylaminophenyl)antimony with copper dichloride. tris(4-N,N-Dimethylaminophenyl)antimony difluoride benzene disolvate II was synthesized from dichloride I and sodium fluoride in aqueous acetone with the subsequent crystallization from benzene. tris(4-N,N-Dimethylaminophenyl)antimony dibenzoate III was obtained from tris(4-N,N-dimethylaminophenyl)antimony and benzoic acid in the presence of hydrogen peroxide in ether or from silver benzoate and the corresponding dichloride in acetone. According to X-ray studies Sb atoms in two crystallographically independent molecules of dichloride, difluoride benzene solvate, and dibenzoate have the distorted trigonal bipyramide coordination [ClSbCl, FSbF, and OSbO trans angles are 178.12(2)°, 178.57(3)°, 177.30°, and 176.49° respectively). Sb-Cl, Sb-F, and Sb-O interatomic distances are 2.4719(7)-2.505(7); 2.106(4); 2.438(2); 2.1212(13) Å respectively. The oxygen atoms of carbonyl groups of the molecule III (C _2v molecular symmetry) are coordinated to the central atom [Sb-O distance 2.987(1) Å].     

Crystal and molecular structures of tris (p-methoxyphenyl)- and tris(2,4, 6-trimethylphenyl)tin(IV) acetates

The crystal and molecular structures of tris(p-anisyl)tin acetate (1) (p-anisyl = p-methoxyphenyl) and trimesityltin acetate (2) (mesityl = 2,4,6-trimethylphenyl) have been determined. Both have monomeric structures with the acetate group acting as an asymmetric bidentate ligand. Bond valence analysis of (1) and (2) and other Ph₃SnO₂CR suggest however that the carboxylate ligand effectively occupies a single bonding position at tin. Thus in (1) and (2) the tin atom is in a chemical environment equivalent to that found in four-coordinate R₃Sn-X systems based on tetrahedral geometry.     

Synthesis of new antimony(III) and bismuth(III) aryl compounds: Crystal and molecular structure of tris(5-bromo-2-methoxyphenyl)antimony

Tris(5-bromo-2-methoxyphenyl)antimony (I) (yield, 85%) and tris(5-bromo-2-methoxyphenyl)bismuth (II) (yield, 81%) were obtained by reacting 5-bromo-2-methoxyphenyllithium with antimony(III) chloride and bismuth(III) chloride, respectively. According to X-ray diffraction data, the antimony atom in I is highly coordinated. The Sb-C bonds lengths are 2.160(1) Å, 2.163(1) Å, and 2.157(2) Å; the Sb…O distances are 2.985(1) Å, 3.051(1) Å, and 3.052(1) Å. The CSbC bond angles vary in the range of 92.19(6)°-94.52(6)°. Molecules of I are linked via Sb(A)…Br(B) intermolecular contacts (3.742(2) Å) to form polymer chains.     

Synthesis,structure, and reactions of tris(4-fluorophenyl)antimony dibromide

The interaction of tris(4-fluorophenyl)antimony with copper(II) bromide in acetone has afforded tris(4-fluorophenyl)antimony dibromide; recrystallization of the product from ethanol has yielded the (4-FC₆H₄)₃SbBr₂·[(4-FC₆H₄)₃SbBr]₂O adduct. [(4-FC₆H₄)₃SbCNS]₂O oxide has been prepared from tris(4-fluorophenyl)antimony dibromide and potassium thiocyanate in aqueous-acetone solution. Antimony atoms in the molecules of the prepared compounds exhibited the distorted trigonal bipyramid coordination with the electron-accepting ligands in the axial positions.     

Synthesis and structure of tris(4-fluorophenyl)antimony dicarboxylates

The interaction of tris(4-fluorophenyl)antimony with chloroacetic, 4-nitrophenylacetic, and benzoic acids in diethyl ether in the presence of tert-butyl hydroperoxide has yielded tris(4-fluorophenyl)antimony dicarboxylates, their Sb atoms bearing distorted trigonal bipyramid coordination with the carboxylate ligands in the axial positions. The intramolecular contacts between Sb atom and carbonyl O atom are formed in the molecules of the products. Their crystal packing is determined by weak intermolecular hydrogen bonds of the H···F and H···O=C types.     

Syntheses and structures of tris(<Emphasis Type="Italic">para</Emphasis>-tolyl)-, tris(3-fluorophenyl)-, and tris(4-fluorophenyl)antimony dioximates

Tris(para-tolyl)antimony bis(2-oxybenzaldoximate) (I), tris(para-tolyl)antimony bis(2-nitrobenzaldoximate) (II), tris(para-tolyl)antimony bis(2-bromobenzaldoximate) (III), tris(3-fluorophenyl)antimony bis(2-oxybenzaldoximate) (IV), tris(4-fluorophenyl)antimony bis(2-bromobenzaldoximate) (V), and tris(4-fluorophenyl)antimony bis(2-nitrobenzaldoximate) (VI) are synthesized by the reactions of tris(paratolyl)-, tris(3-fluorophenyl)-, and tris(4-fluorophenyl)antimony with 2-oxy-, 2-nitro-, and 2-bromobenzaldoxime in diethyl ether in the presence of tert-butyl hydroperoxide. The Sb atoms in complexes I–VI have a distorted trigonal bipyramidal coordination mode with the oximate ligands in the axial positions. CIF files CCDC nos. 1062231 (I), 1059962 (II), 1465384 (III), 1465109 (IV), 1471948 (V), and 1060387 (VI).     

Pseudoheptacoordination and pseudohexacoordination in tris(2-N,N-dimethylbenzylamino)phosphane

The phosphane (C(6)H(4)-2-CH(2)NMe(2))(3)P (1) upon recrystallization from various solvents yielded the structurally different forms 1A, 1C, 1B(1), and 1B(2). Phosphane oxide (C(6)H(4)-2-CH(2)NOMe(2))(3)PO (2) was obtained from 1 by oxidation with hydrogen peroxide. X-ray analysis provided molecular structures for 1A, 1B(1), 1B(2), and 2. Phosphanes 1A and 1B(1) have pseudohexacoordinate frameworks as a result of the formation of two P-N donor interactions, 1B(2) has a pseudoheptacoordinate geometry due to the presence of three P-N interactions, and 2 resides in a tetrahedral geometry. The presence of the flexible dimethylaminobenzyl group in 1A, 1C, 1B(1), and 1B(2) is reasoned to be responsible for this variation in coordination geometry. Phosphane oxide 2 has very strong donor oxygen atoms from N-oxide groups but they are involved in competition with the presence of hydrogen bonding, which results in the lack of donor coordination. High-resolution (1)H, (13)C, and (31)P NMR measurements are also reported. The results provide evidence for the low-energy threshold required to allow hypercoordinated phosphorus to alter coordination geometry.     

Crystal structure of nitrate tris(4-allylthiosemicarbazide)-chromium(III) hydrate

The crystal structure of nitrate tris(4-allylthiosemicarbazide)chromium(III) hydrate [CrL₃](NO₃)₃(H₂O)_1.05 (I), where L is 4-allylthiosemicarbazide, is determined. The asymmetric unit of the cell of the crystal structure of I contains a complex of a chromium ion with three bidentate coordinated molecules L. The outer coordination sphere of the central atom contains a disordered water molecule and three nitrate ions. The coordination polyhedron of the chromium atom in complex I is an octahedron. In the crystal, the complexes of the compound under study are joined with each other by the outer-sphere nitrato groups into a three-dimensional branched net of hydrogen bonds.     

Synthesis and some reactions of tris (pentafluorophenyl) antimony compounds

(C₆F₅)₃Sb has been found to react with interhalogens and halo-pseudohalogens, IX(X = Cl, Br, N₃ and NCO), pseudohalogen (SCN), and elemental sulphur to give oxidative addition products (I–VI). (C₆F₅)₃SbS(VI) may also be prepared by the reaction of (C₆F₅)₃SbCl₂ with H₂S. Metathetical reactions of (C₆F₅)₃SbCl₂ with appropriate metallic salts yield covalent pentacoordinate disubstituted products (V, VII–XII) of the general formula, (C₆F₅)₃SbY₂ (Y = NCS, NCO, ?ONCMe₂, ?ONCMePh $\text{?NCO(CH}{}_2\text{)}{}_2\text{C}$O and p-NO₂C₆H₄OCO). Treatment of (C₆F₅)₃SbCl₂ with aqueous NaN₃ gives the binuclear oxo-bridge compound, [(C₆F₅)₃SbOSb(C₆F₅)₃](N₃)₂·(III) and (IV) are also accessible by displacement reaction of (I) or (II) with the corresponding metallic salt. Molecular weight, conductance measurements, and IR spectra on the new organoantimony(V) derivatives have been obtained.Reductive cleavage reactions of (C₆F₅)₃SbS with hexaaryldileads, Ar₆Pb₂(Ar = Phenyl, p-tolyl) produce (C₆F₅)₃Sb and the corresponding bis(triaryllead) sulphide but treatment of (C₆F₅)₃SbX₂(X = NCO, Cl) with Ar₆Pb₂ gave Ar₄Pb and Ar₂PbX₂ together with (C₆F₅)₃Sb.(C₆F₅)₃SbCl₂ and bis(triorganotin)sulphides undergo exchange of anionic groups.     

Reaction of 4-(N,N-Dimethylaminophenyl)magnesium Bromide with Palladium Tetrakis(triphenylphosphine)

The influence of reaction conditions on catalyzed by Pd(PPh₃)₄ cross-coupling of 4-N,N-dimethylaminophenylmagnesium bromide with 4-bromobenzonitrile in tetrahydrofuran was investigated. The yield of the product of the catalytic process, 4-N,N-dimethylamino-4'-cyanobiphenyl, and of the main product of noncatalytic process, 4-N,N-dimethylaminophenyl 4'-bromophenyl ketone, is mainly governed by the order of introduction of reagents and catalyst into the reaction zone. Experimental observations and analysis of side products suggested conclusions on the processes resulting in deactivation of the catalyst.