Synthetic applications of organoantimony compounds

A systematic study was performed to examine the possibilities of the B3LYP DFT method in a dgdzvp full-electron basis and of the method including a pseudopotential for iodine compounds. The full-electron basis generally gives better agreement for X-I bond lengths and reaction enthalpies of iodination of organic compounds and equally good agreement in calculations of the IR vibrations of the X-I bond length compared with the studies using the pseudopotential. The full-electron basis also allows adequate calculations of the quadrupole coupling constants of iodine atoms and is generally characterized by smaller computing times.

Comparative analysis of a full-electron basis set and pseudopotential for the iodine atom in dft quantum-chemical calculations of iodine-containing compounds

Publisher Summary The chapter focuses on the pentaalkyls and alkyidene trialkyls of the group V elements. The revived interest in this area led to new efforts for improved methods of synthesis for pure alkylidene trialkyls (ylides), for the detection and possible characterization of a pentaalkylphosphorane species, and for a better understanding of the state of structure and bonding in ylides and pentaalkyls. This recent work is summarized in this chapter with the main focus directed to some of the very simple compounds and their silicon derivatives, which have turned out to be of special significance. These derivatives have not only provided new synthetic pathways but also have shown improved thermal stability (as in the case of arsenic ylides) and a modified pattern of chemical reactivity. The broad scope of phosphorus ylides and pentaorganophosphorane chemistry was covered in the leading multivolume series on organophosphorus chemistry. The recent success of efforts to synthesize pentaalkyls [Nb (CH,) 5 ] and even ylides ([ ( CH 3 ) 3 CCH 2 ] 3 TaCHC( CH 3 ) 3 ) of the subgroup metals vanadium, niobium, and tantalum add a new dimension to the scope of this chapter. Alkylidene triorganophosphoranes (phosphorus ylides) are known with a large variety of substituents both at the phosphonium center and at the carbanionic function. The chapter also describes the biochemistry of arsenic ylides and pentaalkylarsoranes.

Pentaalkyls and Alkylidene Trialkyls of the Group V Elements

13 – Arsenic, Antimony and Bismuth

Coordination compounds based on copper(II) halides with 4H-1,2,4-triazolo[1,5-a]benzimidazole (L1), 3-methyl-1,2,4-triazolo[1,5-a]benzimidazole (L2), and 4-methyl-1,2,4-triazolo[1,5-a]benzimidazole (L3) with the compositions [Cu(L1)2(Hal)2]·nH2O (Hal = Cl−, n = 0.5 (I) Br−, n = 1 (II)); [Cu(L2)2Cl2] (III), [Cu(L3)2Cl2] (IV) and [Cu(L3)2Br2(H2O)]·2H2O (V) were synthesized. The compounds were characterized using X-ray diffraction, UV-Vis spectroscopy (diffuse reflectance spectra), infrared spectroscopy, and static magnetic susceptibility measurements. By means of X-ray diffraction structural analysis, crystal structures were determined for the [Cu(L3)2(Hal)2(H2O)]·2H2O complexes, where Hal = Cl− (IVa) or Br− (V). Cytotoxic effects of the complexes and ligands on the cell line Hep-2 were then studied, and we found that the copper(II) complex with ligands L1–L3 leads to a considerable enhancement of cytotoxicity.

Synthesis and magnetic and cytotoxic properties of copper(II) halide complexes with 1,2,4-triazolo[1,5-a] benzimidazoles

Geometrical isomers of stibinous and stibinic propenyl compounds

Very strong asymmetrization of the electron distribution on the central atom occurs for the unsymmetrically substituted compounds of trivalent antimony, which is expressed in a noticeable increase of the asymmetry parameter and the constants of the quadrupole bond for121Sb and123Sb when compared with compounds of the SbX3 type.

Effect of unsymmetrical substitution on the nuclear quadrupole resonance spectra of trivalent antimony

On the sterochemistry of exchange at olefinic carbon

1.

The reaction of diphenylstibine with ethynylbenzene leads to diphenylstyrylstibine.




2.

With carbon tetrachloride diphenylstibine forms chloroform, benzene, chlorodiphenylstibine, and hydrogen chloride, and with benzotrichloride - benzylidene chloride and chlorodiphenylstibine. A reaction scheme is proposed for this process.




3.

The reactions of diphenylstibine with dilute hydrochloric acid, with acetic acid, and with benzoic acid go with liberation of hydrogen and lead, respectively, to chloro-, acetoxy-, and (benzoyloxy)-diphenylstibines.

N. V. Novikova

Papers

Geometrical isomers of stibinous and stibinic propenyl compounds

Effect of unsymmetrical substitution on the nuclear quadrupole resonance spectra of trivalent antimony

On the sterochemistry of exchange at olefinic carbon

Reactivity of diphenylstibine

Organometallic derivatives of ethylene