A 31P and 95Mo NMR study of some molybdenum and tungsten carbonyl complexes of a small air-stable aliphatic phosphine, 1,3,5-triaza-7-phosphadamantane (PTA)

Abstract Complexes of molybdenum and tungsten of the type M(CO) 5 L, M(CO) 4 L 2 and M(CO) 3 L 3 have been prepared, where L = 1,3,5-triaza-7-phosphaadamantane (PTA), a small air-stable aliphatic phosphine. The 31 P coordination chemical shifts indicate a strong σ-interaction between the metals and PTA. The 95 Mo chemical shifts also indicate a large nephelauxetic effect and/or a significant π-interaction of the ligand with molybdenum. Some PTA methyl iodide derivatives of these metal carbonyls have also been prepared and these also have a strong interaction with molybdenum and tungsten through the phosphorus atom of the novel ligand.