Preparation and reactivity of benzo‐1,2‐dichalcogenete derivatives and their bis(triphenylphosphine)platinum complexes

Abstract

The reaction of 4,5‐(o‐xylylenedichalcogeno)‐3,6‐dialkylphthalonitrile (1a‐d) with aluminum chloride in toluene gave ring‐opened products, 3,6‐dialkyl‐4,5‐dicyanobenzene‐1,2‐dithiols (2a,b), for sulfur derivatives and cyclized products, 3,6‐dialkyl‐4‐,5‐dicyanobenzo‐1,2‐diselenetes (2c,d), for selenium derivatives. Asymmetrically substituted 3,6‐diethylbenzo‐1,2‐diselenete (2e) with a bromo and a nitrile group was prepared by the reaction of 4,5‐(o‐xylylenediseleno)‐3,6‐diethyl‐2‐cyano‐1‐bromobenzene (1e) with aluminum chloride in toluene. Compound 2e was unstable compared with 2c and produced an equilibrium mixture of 2e and dimerized dibenzotetraselenocin 3e in the chloroform solution. Compound 2c was reacted with methyl iodide in the presence of sodium hydroxide to produce 1,2‐bis(methylseleno)‐3,6‐diethyl‐4,5‐dicyanobenzene (4) and bis(2‐methylseleno‐3,6‐diethyl‐4,5‐dicyanophenyl)diselenide (5). Compounds 2a and 2c were reacted with tetrakis(triphenylphosphine)platinum in toluene to give the corresponding platinum complexes 6a and 6c with a dichalcogenaplatinumole ring, respectively. The structures of 6a and 6c were determined by NMR, MS, and X‐ray crystallography. To obtain theoretical information, the structures of dichalcogenetes 2a′, 2c, 2e, 2f, 2g and platinum complexes 6a and 6c were optimized by the DFT method using the Gaussian 09 program and their HOMO and LUMO energy levels were calculated by time‐dependent density functional theory.

Improved Synthesis and Coordination Behavior of 1H-1,2,3-Triazole-4,5-dithiolates (tazdt2−) with NiII, PdII, PtII and CoIII

“…With the change of the ligand dppe to PPh 3 in compounds 9a-c, two doublets are observed at the chemical shift between 16.7 ppm and 17.7 ppm. In addition to the 31 P/ 31 P coupling (J P,P = 21.0 Hz), 31 P/ 195 Pt coupling constants between 2861 Hz and 2998 Hz are observed (Table 3), which are in good agreement with other dithiolene-Pt compounds [31,42,43]. Here, the PPh 3 is particularly well-suited for observing changes in the electronic situation of the complex by means of 31 P-NMR spectroscopy [42].…”

Synthesis, structural peculiarities, and photosensitivity of fluorinated dibenzo-1,2,5,6-tetrathiocines

“…1,2,5,6-Tetrathiocines, [1][2][3][4][5][6][7][8] their Se analogues, [2][3][4][5][8][9][10][11][12] and S/Se hybrids 4,5,7 are structurally-flexible eight-membered heterocycles most known with fused (benzo, pyrrolo, thiopheno) derivatives; any Te congeners are not reported. The compounds are relatively less-studied, meanwhile they are of current interest due to chemical reactivity embracing synthesis of new materials; and S incarnations, also due to bioactivity.…”