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A Back‐to‐Back Ligand with Dipyrazolylpyridine and Dipicolylamine Metal‐Binding Domains
Author(s) -
Tovee Clare A.,
Kilner Colin A.,
Barrett Simon A.,
Thomas James A.,
Halcrow Malcolm A.
Publication year - 2010
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200901107
Subject(s) - chemistry , platinum , palladium , pyridine , moiety , nitromethane , medicinal chemistry , transition metal , ligand (biochemistry) , stereochemistry , metal , crystallography , inorganic chemistry , organic chemistry , catalysis , biochemistry , receptor
Reaction of 4‐bromomethyl‐2,6‐bis(pyrazol‐1‐yl)pyridine with dipicolylamine yields 4‐bis(pyrid‐2‐ylmethyl)aminomethyl‐2,6‐bis(pyrazol‐1‐yl)pyridine ( L ). Treatment of L with [MCl 2 (NCPh) 2 ] (M = Pd, Pt) in the presence of AgPF 6 affords [MCl( L )]PF 6 , whose palladium or platinum centre is bound exclusively by the dipicolylamino moiety of L , as established by NMR spectroscopy. The pendant dipyrazolylpyridine residue in these compounds is complexed by iron(II) to form [Fe{MCl(μ‐ L )} 2 ][PF 6 ] 4 (M = Pd, 1 ; M = Pt, 2· n H 2 O). The nitromethane solvate crystal of 1 contains low‐spin iron centres at 150 K. However, dried 1 and 2· n H 2 O are predominantly high‐spin at room temperature, undergoing very gradual thermal spin transitions upon cooling to ≤ 50 % completeness. The platinum compound also undergoes a thermal spin transition in CD 3 NO 2 solution, with T 1/2 = 253 K.