TY - JOUR
T1 - Synthesis and structural characterisation of heavy alkaline earth N, N′-bis(aryl)formamidinate complexes
AU - Cole, Marcus L
AU - Deacon, Glen Berenger
AU - Forsyth, Craig Macdonald
AU - Konstas, Kristina
AU - Junk, Peter Courtney
PY - 2006/7/4
Y1 - 2006/7/4
N2 - Treatment of calcium or strontium with 2.0 equivalents of N, N′-bis(o-methylphenyl)formamidine (o-TolFormH), N, N′-bis(2,6-dimethylphenyl)formamidine (XylFormH) or N, N′-bis(o-phenylphenyl)formamidine (o-PhPhFormH) in the presence of 1.0 equivalent of Hg(C6F5)2 in tetrahydrofuran (thf) affords the bis(formamidinate) complexes [Ca(o-TolForm)2(thf)2] (1), [Ca(XylForm)2(thf)2] (2), [Ca(o-PhPhForm)2(thf)2]·thf (3), [Sr(o-TolForm)2(thf)3] (4), [Sr(XylForm)2(thf)3]·3thf (5) and [Sr(o-PhPhForm)2(thf)3]·2thf (6). Analogous reactions with barium were generally unsatisfactory but [Ba(o-PhPhForm)2(thf)3]·2thf (7) was successfully prepared. Compounds 1–7 have been characterised by various spectroscopic methods (1H, 13C(1H) NMR and IR), elemental analyses and, for 1, 2 and 4–6, X-ray crystallography. The calcium complexes are monomeric and six-coordinate with either transoid octahedral or trigonal prismatic geometry, whilst the larger radius of strontium accommodates an additional thf solvent donor to give seven-coordinate structures with two types of coordination polyhedra.
AB - Treatment of calcium or strontium with 2.0 equivalents of N, N′-bis(o-methylphenyl)formamidine (o-TolFormH), N, N′-bis(2,6-dimethylphenyl)formamidine (XylFormH) or N, N′-bis(o-phenylphenyl)formamidine (o-PhPhFormH) in the presence of 1.0 equivalent of Hg(C6F5)2 in tetrahydrofuran (thf) affords the bis(formamidinate) complexes [Ca(o-TolForm)2(thf)2] (1), [Ca(XylForm)2(thf)2] (2), [Ca(o-PhPhForm)2(thf)2]·thf (3), [Sr(o-TolForm)2(thf)3] (4), [Sr(XylForm)2(thf)3]·3thf (5) and [Sr(o-PhPhForm)2(thf)3]·2thf (6). Analogous reactions with barium were generally unsatisfactory but [Ba(o-PhPhForm)2(thf)3]·2thf (7) was successfully prepared. Compounds 1–7 have been characterised by various spectroscopic methods (1H, 13C(1H) NMR and IR), elemental analyses and, for 1, 2 and 4–6, X-ray crystallography. The calcium complexes are monomeric and six-coordinate with either transoid octahedral or trigonal prismatic geometry, whilst the larger radius of strontium accommodates an additional thf solvent donor to give seven-coordinate structures with two types of coordination polyhedra.
UR - http://www.scopus.com/inward/record.url?scp=85034344261&partnerID=8YFLogxK
U2 - 10.1039/b602210c
DO - 10.1039/b602210c
M3 - Article
SN - 1477-9226
SP - 3360
EP - 3367
JO - Dalton Transactions
JF - Dalton Transactions
IS - 27
ER -