New Types of Group 4 and 13 Metal Complexes Stabilized by Homo- or Hetero-Donor Functionalized Dicarbollide Ligands: Syntheses, Characterizations, and Structural Studies of [{eta(5)-C2B9H9(D)}(eta(1)-NMe2CH2)]M(NMe2)(2) (D = CH2NMe2, PPh2; M = Ti, Zr) and [(eta(1)-D)(eta(1)-NMe2CH2)C2B9H10]MMe2 (D = CH2NMe2, PPh2; M = Al, Ga)

Abstract

A series of group 4 and 13 metal complexes coordinated to either a homo- or hetero-donor and a dicarbollyl ligand derived from N,N'- or P,N-chelated ligands were Synthesized and characterized. Two homo- and hetero-donor tethered ligands of the type 7,8-(Me7NCH2)(mu-H)(Me2NCH2)-7,8-C7B9H10 (Dcab(N,N), 3) and 7-PPh2-8-Me7NHCH2-7,8-C2B9H10 (Dcab(P,N)H, 6) were prepared using the standard deborination methods from 1,2-(NMe2CH2)(2)-1,2-C2B10H10 (2) and 1-PPh2-2-Me2NCH2-1,2-C2B10H10 to (5), respectively. Subsequent reactions of 3 with M(NMe2)(4) (M = Ti, Zr) produced single nitrogen donors involving pi,sigma-dicarbollides of the type [{eta(5)-C2B9H9(CH2NMe2)}(eta(1)-NMe2CH2)]M(NMe2)(2) (M =Ti (4), Zr (5)). Structurally similar nitrogen donor stabilized rap-dicarbollides of the type [{eta(5)-C2B9H9(PPh2}(eta(1)-NMe2CH2)]M(NMe2)(2) (M = Ti (7), Zr (8)) were produced from the reaction of 6 with M(NMe2)4(M =Ti, Zr). When group 13 metals were attempted with dissimilar ligands, 3 and 6, up-type complexes were formed with the engagement of two tethered donors at the dicarbollide ligand in an exo-polyhedral manner irrespective of the dissimilar donor properties, nitrogen or phosphine. As a result, a series of group 13 metal complexes bearing ligands 3 and 6, [(eta(1)-NMe2CH2)(2)C2B9H10]M Me-2 Me, (M = Al (11), Ga (12)) and [(eta(1)-PPh2)(eta(1)-NMe7CH2)C2B9H11M Me-2 (M =Al (13), Ga (14)), were prepared by reacting 3 and 6 with trimethylaluminum (TM A) and trimethylium G), respectively. New types of pi,sigma- and sigma,sigma-coordination were established by extensive structural studies of each metal complex comprising N,N'- or P,N-chelated dicarbollide: 7, 9, 10, 11, 13, and 14.