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Title: Aluminum alkyl complexes containing guanidinate ligands

Journal Article · · Organometallics
DOI:https://doi.org/10.1021/om980223m· OSTI ID:655371
; ; ;  [1];  [2]
  1. Univ. of Iowa, Iowa City, IA (United States). Dept. of Chemistry
  2. Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry

The synthesis and structures of new aluminum complexes incorporating guanidinate ligands (R{sub 2}NC(NR{prime}){sub 2}{sup {minus}}) are described. The reaction of {sup i}PrN{double_bond}C{double_bond}N{sup i}Pr with LiNR{sub 2} reagents yields Li[R{sub 2}NC(N{sup i}Pr){sub 2}] guanidinate salts, which are reacted in situ with AlCl{sub 3} or AlMe{sub 2}Cl to afford {l_brace}R{sub 2}NC(N{sup i}Pr){sub 2}{r_brace}AlCl{sub 2} (1a, R = Me; 1b, R = Et; 1c, R = {sup i}Pr; 1d, R = SiMe{sub 3}) or {l_brace}R{sub 2}NC(N{sup i}Pr){sub 2}{r_brace}AlMe{sub 2} (2a, R = Me; 2b, R = Et; 2c, R = {sup i}Pr), respectively. The reaction of 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) with AlMe{sub 3} generates {l_brace}({mu}-hpp)-AlMe{sub 2}{r_brace}{sub 2} (3). Complexes 1a, 1d, and 3 have been characterized by X-ray crystallography. 1a and 1d adopt monomeric structures with symmetric chelated bidentate guanidinate ligands. Delocalization of the {minus}NR{sub 2} lone pair into the chelate ring is important for 1a but not for 1d, due to N-Si {pi}-bonding and steric crowding. The bicyclic structure of the hpp{sup {minus}} ligand enforces a dimeric {mu}-hpp{sup {minus}} structure for 3.

Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FG02-88ER13935
OSTI ID:
655371
Journal Information:
Organometallics, Vol. 17, Issue 15; Other Information: PBD: 20 Jul 1998
Country of Publication:
United States
Language:
English