Porphyrin “Flying-Saucers”:  Solid State and Solution Structure of a Novel Pentameric Array of Axially-Ligated Canted Porphyrins

Abstract

The pentameric array of canted porphyrins (3‘TPyP)[Ru(TPP)(CO)]4 (1) (3‘TPyP = 5,10,15,20-tetra(3‘-pyridyl)porphyrin, TPP = meso-tetraphenylporphyrin) was synthesized by axial coordination of the 3‘N pyridyl groups of 3‘TPyP to the ruthenium core of four Ru(TPP)(CO) units; a thorough spectroscopic characterization of 1 in solution, together with a well-defined X-ray structure of the corresponding zinc derivative (Zn·3‘TPyP)[Ru(TPP)(CO)]4 (1Zn), is reported.

Side-to-Face Ruthenium Porphyrin Arrays: Photophysical Behavior of Dimeric and Pentameric Systems

“…For example, when the metal is Zn, the coordina- tive bond is intrinsically weak. [28,30,31] In some instances, the structure can be obtained from X-ray crystallo-graphic data. when the side porphyrin is bound as a guest into a cyclic host of face metal porphyrins).…”

“…[28] The dimeric [Ru(TPP)(CO)(4'MPyP)] and pentameric (4'TPyP)[Ru(TPP)(CO)] 4 (abbreviations are given in ref. In order to check possible effects of the mutual orientation of the porphyrin rings, an analogous series of canted side-to-face arrays was recently synthesized [30] with 3'-pyridyl substituents as connecting groups. Analogous species that contain a Zn center instead of freebase porphyrin are designated Zn(4)Ru and Zn(4)Ru 4 .…”

“…In order to check possible effects of the mutual orientation of the porphyrin rings, an analogous series of canted side-to-face arrays was recently synthesized [30] with 3'-pyridyl substituents as connecting groups. [30] Related side-to-face arrays based on ruthenium and osmium octaethyl porphyrins have also been recently synthesized. The analogous pentameric species (3'TPyP)[Ru(TPP)(CO)] 4 (Fb(3)Ru 4 ) is not depicted in Figure 1 for practical reasons.…”

On the structure of unsolvated free-base 5,10,15,20-tetra(3-pyridyl)porphyrin

“…The title compound, 5,10,15,20-tetra(3-pyridyl)porphyrin (3TPyP) (1) (Scheme 1a), has also been used similarly but less frequently. Polynuclear metallosupramolecular complexes [12,13], two coordination polymers [14,15] and trigonal prismatic shaped coordination cages [16][17][18] bearing either free-base 1 or its Zn 2+ core metalated derivative have been reported. Most recently, Lipstman and Goldberg reported a series of coordination polymers based on 3TPyP and various metal ions [19,20].…”

18 Supramolecular coordination chemistry

“…bromobenzene) in the cavity, depending on the pH. 115,116 Larger arrays based on the same construction principle include 7-membered, 117 8-membered (Fig. 12).…”