Carbonyl-molybdenum complexes of the hydrotris(3,5-dimethyl-1,2,4-triazol-1-yl) borate ligand

• Published in: Journal of organometallic chemistry Vol. 506; no. 1; pp. 301 - 306
• Main Authors: Macleod, Ian T., Tieknik, Edward R.T., Young, Charles G.
• Format: Journal Article
• Language: English
• Published: LAUSANNE 1 Elsevier B.V 1996; Elsevier
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Crystal structure; Mass spectrometry; Molybdenum; NMR spectroscopy; Physical Sciences; Science & Technology; Triazolyborate; Tricarbonyl; Triazolyborate; Tricarbonyl; NMR spectroscopy; Molybdenum; Mass spectrometry; Crystal structure; COORDINATION CHEMISTRY; tricarbonyl; BEHAVIOR; crystal structure; mass spectrometry; triazolylborate; IR spectroscopy; PYRAZOLE-DERIVED LIGANDS; molybdenum; POLYPYRAZOLYLBORATE LIGANDS
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/0022-328X(95)05764-G

The reaction of KBH 4 with 3 equiv. of 3,5-dimethyl-1,2,4-triazole at ca. 230°C yielded potassium hydrotris(3,5-dimethyl-1,2,4-triazol-1-yl) borate, K{HB(Me 2tz) 3}. The reaction of Mo(CO) 6 and K{HB(Me 2tz) 3} in N, N-dimethylformamide at 110°C gave [{HB(Me 2tz) 3}Mo(CO) 3] −, which was isolated as the salt NEt 4[{HB(Me 2tz) 3}Mo(CO) 3] ( 1). Crystal characterisation of 1 revealed a six-coordinate, distorted octahedral anion composed of a facial, tridentate HB(Me 2tz) 3 − ligand and three mutually cis (facial) carbonyl ligands. Spectroscopic data were consistent with greater electron-withdrawal by the triazolyborate ligand than by the related hydrotris(3,5-dimethylpyrazol-1-yl)borate ligand. Reaction of 1 with iodine gave {HB(Me 2tz) 3}Mo(CO) 3I, which was spectroscopi characterised as a seven-coordinate 3:3:1 face-capped octahedral complex.