The past few years have seen an increasing research interest in the use of the sterically demanding trialkylsiloxy group as a ligand in coordination chemistry. The very bulky ligand tri-tert-butylsiloxy (But3SiO) has been used to stabilize low coordination number transition metal compounds, yielding interesting structures and reactivities. Triphenylsiloxy (Ph3SiO) has been extensively used in lanthanide alkoxide chemistry.
Our interest has been in the development of new oxo siloxy complexes of MoVI. The utilization of triphenylsiloxy in place of trimethylsiloxy not only increases the solubility of the product, but also increases the air stability and prevents the possible oligomerization through the siloxy group. In our work we have found a very simple preparation of triphenylsiloxy compounds through the direct silylation of metal oxides. One of the interests of our work has been in the oxygen atom transfer reaction. During a study of the oxygen atom transfer reaction of MoO2(OSiPh3)2 (I) with triphenylphosphine the compound MoO2(OSiPh3)2(PPh3) (II) was discovered. Compound (II) contains a rare Mo(VI)-phosphine bond, which may have implications for the mechanism of the oxygen atom transfer reaction. The structure of (II) is shown below.
Additional work involves reactions of compound (I) and similar dioxo molybdenum compounds with alkylating agents such as dimethyl zinc and tetramethyl tin.
The past few years have seen an increasing research interest in the use of the sterically demanding trialkylsiloxy group as a ligand in coordination chemistry. The very bulky ligand tri-tert-butylsiloxy (But3SiO) has been used to stabilize low coordination number transition metal compounds, yielding interesting structures and reactivities. Triphenylsiloxy (Ph3SiO) has been extensively used in lanthanide alkoxide chemistry.
Our interest has been in the development of new oxo siloxy complexes of MoVI. The utilization of triphenylsiloxy in place of trimethylsiloxy not only increases the solubility of the product, but also increases the air stability and prevents the possible oligomerization through the siloxy group. In our work we have found a very simple preparation of triphenylsiloxy compounds through the direct silylation of metal oxides. One of the interests of our work has been in the oxygen atom transfer reaction. During a study of the oxygen atom transfer reaction of MoO2(OSiPh3)2 (I) with triphenylphosphine the compound MoO2(OSiPh3)2(PPh3) (II) was discovered. Compound (II) contains a rare Mo(VI)-phosphine bond, which may have implications for the mechanism of the oxygen atom transfer reaction. The structure of (II) is shown below.
Additional work involves reactions of compound (I) and similar dioxo molybdenum compounds with alkylating agents such as dimethyl zinc and tetramethyl tin.