Synthesis and characterization of extremely bulky amido-germanium(II) halide complexes

Abstract

The extremely bulky aryl/silyl secondary amines, HN(Ar)(SiMe3), Ar = C6H2-i-Pr2(CPh3)-2,6,4 (LDipH), C6H2{C(H)Ph2}2-i-Pr-2,6,4 (L†H), or C6H2{C(H)Ph2}2-t-Bu-2,6,4 (Lt-BuH), have been synthesized via salt metathesis reactions between the appropriate lithium anilide complex and ClSiMe3. The related diaryl secondary amines, HN(Ar*)(R), Ar* = C6H2{C(H)Ph2}2Me-2,6,4 and R = C6H3Me2-3,5 (LMeH), C6H3(CF3)2-3,5 (LCF3H), or C6H2-i-Pr3-2,4,6 (LTripH), were prepared via palladium catalyzed cross-coupling reactions. Three of the amines were crystallographically characterized. Treatment of GeCl2·dioxane with 1 equiv. of each of the deprotonated amines led to the isolation of the amido-germanium(II) chloride complexes, [LGeCl] (L = L†, Lt-Bu, LCF3, or LTrip). Similarly, reaction of the known amido-digermyne, [L*Ge–GeL*] (L* = –N(Ar*)(SiMe3)), with I2 resulted in the oxidative cleavage of the Ge–Ge bond of the digermyne, and the formation of the first two-coordinate amido-germanium(II) iodide complex, [L*GeI]. Crystallographic characterization of [Lt-BuGeCl] and [L*GeI] revealed both to have similar monomeric structures. The compounds described in this study should prove useful as synthons for synthetic chemists working in the field of low oxidation state main group chemistry.