RESUMO
Reaction of the novel ligand 3-(2'-pyridyl)-benzo-1,2,4-thiadiazine (L) with the transition metal chloride salts MCl2·xH2O (M(II) = Mn, Fe, Co, Cu and Zn) in a 2 : 1 mole ratio afforded the mononuclear octahedral (high spin) complexes L2MCl2 (1a-1e respectively) in which L binds in a chelate fashion via N(2) and the pyridyl N atoms. In the case of CuCl2 the intermediate 1 : 1 four-coordinate complex LCuCl2 (2) was also isolated which adopts a polymeric structure with pseudo-square planar molecules linked via long Cu···S contacts (d(Cu···S) = 2.938(1) Å) in the apical position. In the presence of non-interacting ions, 3 : 1 complexes are isolated, exemplified by the reaction of L with Fe(CF3SO3)2 in a 3 : 1 ratio which affords the low spin complex [L3Fe][CF3SO3]2 (3). Reaction of L with VCl3 in a 2 : 1 mole ratio under aerobic conditions afforded the vanadyl complex [L2V(=O)Cl][Cl] (4).
RESUMO
The coordination of AlCl(3) by the complex [{MeAl(2-py)(3)}Li.thf] () gives the unusual product [{MeAl(2-py)(3)}(2)Al](+)[{MeAl(2-py)(3)}Li](2)(mu-Cl)(-) (), in which the [MeAl(2-py)(3)](-) aluminate anion of acts cooperatively in the coordination of an Al(3+) cation and Cl(-) anion.
RESUMO
A series of tris-pyridyl complexes [RAl(2-py)(3)]Li.thf [2-py = 2-pyridyl; R = Et (1); (n)Bu (2); (s)Bu (3), (t)Bu (4)] were prepared by the sequential reaction of AlCl(3) with RLi then 2-Li-py in thf. The related complexes [MeAl{2-(3-Me)py}(3)]Li(mu-Br)Li(thf)(3) (5), [MeAl{2-(5-Me)py}(3)]Li.thf (6) and [MeAl{2-(6-Me)py}(3)]Li.thf (7) are obtained similarly from MeAlCl(2) and the appropriate lithio-pyridine (2-Li-py'). The synthetic approaches used provide the means for extensive elaboration of the [RAl(2-py')(3)](-) ligand frameworks, and potentially broad access to a large range of new anionic tris-pyridyl ligands of this type. Fundamental insights into how the ligand bites and coordination environments offered are modified by substituents at the Al bridgehead and pyridyl rings are given by the solid-state structures of 1-7 .