Group 11 amidinates and guanidinates: Potential precursors for vapour deposition

Several guanidinates of copper and silver, as well as amidinates and guanidinates of gold were synthesized as potential precursors for vapour deposition methods. These compounds were found to be dimers in the case of copper and gold, and trimers in the case of silver. The copper compounds showed good thermal and photostability, and were isolable by sublimation. The silver compounds proved to be very reactive to both heat and light, and were found to deposit silver metal when heated, suggesting that these sensitive compounds might be used as single source precursors. The gold compounds were found to exhibit some heat and light sensitivity, but were much more stable than their silver counterparts. Specifically, [Au(NiPr)2NMe2] 2 (8) was found to be sublimable at 85 °C and 20 mTorr, and deposited gold metal under higher temperatures. These metal-depositing thermal reactions were thought to abstract a hydrogen from the guanidinate ligand, which acts as the reducing agent. Interestingly, the gold amidinate compounds were found to produce diisopropylcarbodiimide when heated, suggesting that these compounds deinsert carbodiimide rather than abstract a hydrogen atom from the ligand