Synthesis and reactivity of Group 6 metal carbonyl complexes containing bis(triazol-1-yl)methane: linkage coordination polymers

Abstract The reaction of bis(3,5-dimethyl-1,2,4-triazol-1-yl)methane, CH 2 (3,5-Me 2 Tz) 2 , with M(CO) 6 (M=Cr, Mo or W) in refluxing DME produces CH 2 (3,5-Me 2 Tz) 2 M(CO) 4 in moderate yield. The crystal structures determined by X-ray analysis show that bis(3,5-dimethyl-1,2,4-triazol-1-yl)methane acts as a chelating bidentate ligand with two endodentate nitrogen atoms in these complexes. Reactions of complexes CH 2 (3,5-Me 2 Tz) 2 M(CO) 4 (M=Mo or W) with R 2 SnX 2 (R=Ph or Me; X=Cl or Br) in a 1:1 or 1:2 ratio, respectively, only yield 1:1 adducts. In these adducts, bis(3,5-dimethyl-1,2,4-triazol-1-yl)methane may coordinate to tin atom through exodentate nitrogen atoms on the 4-position of triazole rings to form linkage coordination polymers. Possibly owing to weak donors of 4-position exonitrogen atoms on triazole rings to organotin acceptors, the dissociation of these adducts in solution could exist. Adduct of CH 2 (3,5-Me 2 Tz) 2 W(CO) 4 ·SnPh 2 Br 2 absorbs one water molecule while crystals are growing and becomes the hydrolysis product [SnPh 2 Br 2 (H 2 O)]·(CH 2 (3,5-Me 2 Tz) 2 W(CO) 4 ), which is characterized by X-ray crystallography, indicating that tin atom is five coordinate with a trigonal bipyramid geometry, the water molecule coordinates to the tin atom, and is simultaneously connected to the exonitrogen atoms on the 4-position of triazole rings of two adjacent CH 2 (3,5-Me 2 Tz) 2 W(CO) 4 units through hydrogen bonds to form linkage coordination polymers, in which two coordination modes are observed.