Ligand-Bridged Heterobimetallic Polymers:  Silver(I)−Benzothiadiazole−Nickel Porphyrin Cation−Benzothiadiazole Arrays

Abstract

Stable crystals of (NiOETPP(BTD)2 +)(Ag+)(ClO4)2·2CH2Cl2 were obtained from the oxidation of NiOETPP with AgClO4 in CH2Cl2 followed by addition of BTD. (OETPP = 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin; BTD = 2,1,3-benzothiadiazole). An X-ray structure reveals that the complex is a bimetallic polymeric aggregate composed of [−Ag+−BTD−NiP+−BTD−] subunits in which the BTDs act as bidentate ligands that bind to the Ni and Ag ions via their their two nitrogens. As in the parent NiOETPP, the ligated oxidized porphyrin adopts a severely distorted saddle conformation. The saddle distortion and peripheral substituents form superstructural trenches that control the orientations of the two BTD axial ligands which are forced into a nearly orthogonal configuration along the axes defined by opposite porphyrin nitrogens.

Unusual solvent dependent electronic absorption spectral properties of nickel(II) and copper(II) perhaloporphyrins

“…Similar behavior was reported for the ligation of piperidine to NiTPP [65] and other Ni(II) porphyrins [64]. In the solid-state, the Ni(II) porphyrins are known to exhibit six coordinate geometry [96][97][98][99][100][101][102].…”

High-valent transition metal centers and noninnocent ligands in metalloporphyrins and related molecules: a broad overview based on quantum chemical calculations

“…Fajer and co-workers [70] have reported an oxidized nickel porphyrin, [Ni(OETPP)(BTD)] + (OETPP= b-octaethyl-meso-tetraphenylporphyrin, BTD=2,1,3-benzothiadiazole), with an EPR spectrum typical of hexacoordinate Ni(III) with the unpaired electron in the d z2 orbital. The Ni-N distances are 2.00 and 2.23 A Ê for the porphyrin and axial nitrogens, respectively.…”

Dimensionality Control in Crystalline Zinc(II) and Silver(I) Complexes with Ditopic Benzothiadiazole-Dipyridine Ligands

“…In the solid state, the BTD fragment generally engages in a variety of supramolecular interactions such as hydrogen bonding, chalcogen N•••S bonding and π-π stacking interactions [14,16,17]. Moreover, the presence of two sp 2 nitrogen atoms on the thiadiazole ring confers coordinating properties to the BTD unit, which have been exploited, for example, in several transition metal complexes where BTD acted as monotopic [18] or ditopic ligand [19][20][21][22][23]. On the other hand, introduction of coordinating groups on the benzene ring affords neutral or anionic ligands allowing the formation of luminescent discrete complexes or coordination polymers in which the thiadiazole nitrogen atoms can take part, or not, to the coordination of metal centers [24].…”