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Syntheses and characterisation data are reported for the following ReI and PtIV bidentate chelate complexes of oligopyridines, [{ReBr(CO)3}2L] (L=2,2′:6′,2″:6″,2‴-quaterpyridine (QP), or 4′,4″-bis(4-tert-butylphenyl)-2,2′:6′,2″:6″,2‴-quaterpyridine (BPQP)), [(PtIMe3)2 (QP)], [ReBr(CO)3(QP)] and [ReBr(CO)3(BPQNP)] (BPQNP=4′,4‴-bis(4-tert-butylphenyl)-2,2′:6′,2″:6″,2‴:6‴, 2⁗ -quinquepyridine). The mononuclear complexes do not exhibit metallotropic shifts in solution as occur in the three-ring 2,2′:6′,2″-terpyridine complex analogues. This is attributed to the steric effects of the uncoordinated portions of these ligands, which also lead to severe restrictions to rotation of these pendant arms. Such movements were investigated by low temperature NMR spectra. |
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