Rhodium Pyrazolate Complexes as Potential CVD Precursors

Reaction of 3,5-(CF3)(2)PzLi with Rh(mu-Cl)(eta(2)-C2H4)(2) or Rh(mu-Cl)(PMe3)(2) in Et2O gave the dinuclear complexes Rh(eta(2)-C2H4)(2)(mu-3,5-(CF3)(2)-Pz) (1) and [Rh-2(mu-Cl)(mu-3,5-(CF3)(2)-Pz) (PMe3)(4)] (2) respectively (3,5-(CF3)(2)Pz = bis-trifluoromethyl pyrazolate). Reaction of PMe3 with Rh(COD)(mu-3,5-(CF3)(2)-Pz) in toluene gave [Rh(3,5-(CF3)(2)-Pz)(PMe3)(3)] (3). Reaction of 1 and 3 in toluene (1 : 4) gave moderate yields of the dinuclear complex Rh(PMe3)(2)(mu-3,5-(CF3)(2)-Pz) (4). Reaction of 3,5-(CF3)(2)PzLi with [Rh(PMe3)(4)]Cl in Et2O gave the ionic complex [Rh(PMe3)(4)][3,5-(CF3)(2)-Pz] (5). Two of the complexes, 1 and 3, were studied for use as CVD precursors. Polycrystalline thin films of rhodium (fcc-Rh) and metastable-amorphous films of rhodium phosphide (Rh2P) were grown from 1 and 3 respectively at 170 and 130 degrees C, 0.3 mmHg in a hot wall reactor using Ar as the carrier gas (5 cc min(-1)). Thin films of amorphous rhodium and rhodium phosphide (Rh2P) were grown from 1 and 3 at 170 and 130 degrees C respectively at 0.3 mmHg in a hot wall reactor using H-2 as the carrier gas (7 cc min(-1)).