Disturbance of intermolecular forces: eutectics as a new tool for the preparation of vapor-phase deposition precursors.

The volatile bis( tert -butylimido)dichloromolybdenum(VI) compounds, ( t BuN) 2 MoCl 2 ·dad (dad = 1,4-di- tert -butyl-1,3-diazabutadiene) (1) and [( t BuN) 2 MoCl( μ -Cl)·( t BuNH 2 )] 2 (2), form a eutectic, with a two to one composition ( χ 2 = 0.33). A decrease of 40 °C in the melting temperature has been observed between the eutectic mixture and the pure compounds. We have isolated a co-crystal of ( t BuN) 2 MoCl 2 ·dme (dme = 1,2-dimethoxyethane) (3) and 2, also in a two to one ratio, which serves as a structural model for such mixtures. The lower melting point of carefully chosen eutectic mixtures can offer more consistent precursor delivery in deposition processes.