Chemistry of C-Trimethylsilyl-Substituted Heterocarboranes. 25. Syntheses, Structures, and Reactivities of GeCl3-Substituted Half-Sandwich Germacarboranes, closo-1-Ge-2-(SiMe3)-3-(R)-5-(GeCl3)-2,3-C2B4H3 (R = SiMe3, Me, and H)†

Anhydrous GeCl4 reacts with the closo-stannacarboranes 1-Sn-2-(SiMe3)-3-(R)-2,3-C2B4H4 (R = SiMe3 (I), Me (II), and H (III)) in the absence of solvents to give the corresponding closo-germacarboranes 1-Ge-2-(SiMe3)-3-(R)-5-(GeCl3)-2,3-C2B4H3 (R = SiMe3 (IV), Me (V), and H (VI)) in yields of 43%, 22%, and 51%, respectively. Despite the presence of two potential Lewis-acid sites, the reactions of the germacarboranes with the bases C10H8N2, C8H6N4, and C15H11N3 produced exclusively 1-(L)-2-(SiMe3)-3-(R)-5-(GeCl3)-1,2,3-GeC2B4H3 (L = C10H8N2, R = SiMe3 (VII) and Me (VIII); L = C15H11N3, R = SiMe3 (XI)) or, when L = C8H6N4, the bridged complexes 1,1‘-(2,2‘-C8H6N4)-[1-Ge-2-(SiMe3)-3-(R)-5-(GeCl3)-2,3-C2B4H3]2 (R = SiMe3 (IX), Me (X)). The reaction of IV with (η5-C5H5)Fe(η5-C5H4CH2(Me)2N) produced a 1:1 mixture of the salt {[(η5-C5H5)Fe(η5-C5H4CH2]2N(Me)2}+{GeCl3}- (XII) and 1-Ge[(η5-C5H5)Fe(η5-C5H4CH2(Me)2N)]-2,3-(SiMe3)2-5-(NMe2)-2,3-C2B4H3 (XIII), a germacarborane in which a NMe2 group replaced the GeCl3 moie...