title: Behavior of anionic molybdenum(IV, VI) and tungsten(IV, VI) complexes containing bulky hydrophobic dithiolate ligands and intramolecular NH···S hydrogen bonds in nonpolar solvents.
abstract: Molybdenum(IV, VI) and tungsten(IV, VI) complexes, (Et4N)2[M(IV)O{1,2-S2-3,6-(RCONH)2C6H2}2] and (Et4N)2[M(VI)O2{1,2-S2-3,6-(RCONH)2C6H2}2] (M = Mo, W; R = (4-(t)BuC6H4)3C), with bulky hydrophobic dithiolate ligands containing NH···S hydrogen bonds were synthesized. These complexes are soluble in nonpolar solvents like toluene, which allows the detection of unsymmetrical coordination structures and elusive intermolecular interactions in solution. The (1)H NMR spectra of the complexes in toluene-d8 revealed an unsymmetrical coordination structure, and proximity of the counterions to the anion moiety was suggested at low temperatures. The oxygen-atom-transfer reaction between the molybdenum(IV) complex and Me3NO in toluene was considerably accelerated in nonpolar solvents, and this increase was attributed to the favorable access of the substrate to the active center in the hydrophobic environment.
authors.affiliation: Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan. tokamura@chem.sci.osaka-u.ac.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hasenaka
authors.forename: Taka-aki
authors.initials: TA
authors.lastname: Okamura
authors.forename: Miki
authors.initials: M
authors.lastname: Tatsumi
authors.forename: Naoya
authors.initials: N
authors.lastname: Inazumi
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Onitsuka
mesh_terms: D000838:Anions / Q000138:chemical synthesis / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D006860:Hydrogen Bonding; D008024:Ligands; D008958:Models, Molecular; D008982:Molybdenum / Q000737:chemistry*; D012997:Solvents; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D014414:Tungsten / Q000737:chemistry*
chemical_list: D000838:Anions; D056831:Coordination Complexes; D008024:Ligands; D012997:Solvents; D013438:Sulfhydryl Compounds; D008982:Molybdenum; D014414:Tungsten