Volatile N,N′-dialkyl-β-dialdiminate complexes of magnesium and zinc as possible chemical vapor deposition precursors

A series of volatile magnesium(II) and zinc(II) bis(β-dialdiminato) complexes (of stoichiometry M[RN(CH)₃NR]₂ where R = methyl, ethyl, isopropyl, or tert-butyl) have been prepared and investigated as potential precursors for the chemical vapor deposition of thin films. Several of the compounds have been characterized crystallographically; the metal centers adopt pseudo-tetrahedral geometries with the two ligands forming six-membered rings with the metal center. All eight compounds sublime cleanly both in vacuum and under 1 atm of N₂, and the most volatile compounds (those having N-methyl substituents) have vapor pressures of 1 Torr at 88 (Mg) and 90 °C (Zn). In general, metal complexes of N,N′-dialkyl-β-dialdiminate ligands are more volatile than their corresponding N,N′-dialkyl-β-diketiminate and N,N-dialkylamidinate analogues.