THE PREPARATION AND COORDINATION CHEMISTRY OF 2,2'-6',2''-TERPYRIDINE MACROCYCLES .3. TRANSIENT TEMPLATE EFFECTS INVOLVING DIMETHYLTIN(IV)

Complexes of a novel quinquedentate ligand L1, which incorporates a 2,2'':6'',2"-terpyridine moiety, are prepared via template condensations about Ni2+ or Mn2+. The crystal and molecular structure of [NiL1 (EtOH)2][BF4]2 shows the metal to be in a pentagonal-bipyramidal N5O2 environment. The free ligand L1 may be obtained as its dication from template condensations in which there is a mismatch between the donor properties of the ligand and the acceptor properties of the metal ion. [H2L1][PF6]2 may be isolated from the template condensation about Cr3+ or [SnMe2]2+. The crystal and molecular structure of [H2L1][PF6]2 is reported, and the origin of this novel template effect is discussed.