Synthesis and Characterization of Mono-, Bis-, and Tetrakis-Pyridyltriarylporphyrin Pd(II) and Pt(II) Supramolecular Assemblies. Molecular Structure of a Pd-Linked Bisporphyrin Complex¹

Abstract

A series of mono-, bis-, and tetrakisporphyrin assemblies was synthesized from 5-(ppyridyl)-10,15,20-triphenylporphyrin, (pyPP)H2, 5-(p-pyridyl)-10,15,20-tri(p-tolyl)porphyrin, (pyTP)H2, (pyPP)Zn, (pyTP)Zn, and Pt(II) and Pd(II) complexes. Porphyrin subunits assemble around the central metal ions through the pyridyl group. Treating trans-Pd(DMSO)2Cl2 with 2 equiv of the pyridyl porphyrins resulted in the formation of trans-bisporphyrin assemblies Pd[(pyPP)H2]2Cl, Pd[(pyTP)H2]2Cl2, Pd[(pyPP)Zn]2Cl2, and Pd[(pyTP)Zn]2Cl2. Treating cis-Pt(DMSO)2Cl2 with 1 equiv of each pyridylporphyrin produced the cis-monoporphyrin complexes Pt(DMSO)[(pyPP)H2]Cl2, Pt(DMSO)[(pyTP)H2]Cl2, Pt(DMSO)[(pyPP)Zn]Cl2, and Pt(DMSO)[(pyTP)Zn]Cl2. The treatment of Pt(DMSO)(pyPOR)Cl2 with one more equiv of pyridylporphyrin resulted in the formation of cisbisporphyrin assemblies, Pt[(pyPP)H2]2Cl2, Pt[(pyTP)H2]2Cl2, Pt[(pyPP)Zn]2Cl2, and Pt[(pyTP)Zn]2Cl2. Also, the reaction of Pt(DMSO)(pyPOR)Cl2 and 4-pyridyl-4'-methylpyridinium iodide (MQ+I-) afforded cis-porphyrin−Pt−viologen assemblies. Treatment of M(DPPP)(OTf)2 (M = Pt, Pd; DPPP = 1,3-bis(diphenylphosphino)propane; OTf = triflate anion) with 2 equiv of pyridylporphyrin resulted in cis-bisporphyrin assemblies [M(DPPP)[(pyPOR)H2]2](OTf)2 and [M(DPPP)[(pyPOR)Zn]2(OTf)2. Synthesis of tetrakisporphyrin assemblies [M{(pyTP)H2}4]X2 (M = Pt, Pd; X = BF4, OTf) was accomplished by the reaction of [M(CH3CN)4]X2 with (pyTP)H2. Solution 1H NMR studies show that the four porphyrins are equivalent and that the central metals have square planar geometry. The crystal structure of [Pd(DPPP){(pyTP)H2}2](OTf)2 was determined by single-crystal X-ray diffraction analysis (monoclinic,

Metal-Mediated Multi-Porphyrin Discrete Assembliesand Their Photoinduced Properties

“…The geometrical parameters of this structure show significant differences as compared to those reported by Woo and co-workers for the square-planar bisporphyrin complex cis-[Pd(dppp)(4 MPyP) 2 ](OTf) 2 (see above) ( Fig. 7) [51]. In the neutral ruthenium complex (7) the porphyrin centroid-to-centroid distance is 14.9Å, the angle defined by the metal center and the two porphyrin centroids is 98.7 • , and that between the porphyrin mean planes is 83.78 • .…”

“…The angular connectors employed 3 Schematic drawing of the square planar and octahedral metal fragments (and of their precursors) most commonly used in the metal-driven construction of multiporphyrin assemblies so far are relatively few ( Fig. 3 4 ] (X = Cl, Br) have been used as cruciform fragments since they can provide four coplanar coordination sites [51,59].…”

“…We mainly exploited the coordination ability of the two Ru(II) complexes, trans-[RuCl 2 (dmso-S) 4 4 ] (see [51] and [59]) under mild conditions, of two adjacent dmso ligands [75,76] (Fig. 6), which were unambiguously characterized in solution by NMR spectroscopy [65,72,73].…”

Design and Self‐Assembly of Ditopic and Tetratopic Cavitand Complexes

“…[12] The cis-[Pt(dmso) 2 Cl 2 ] complex was reacted with monophenylpyridyl cavitand 6. The different reactivities of the two DMSO ligands allowed the reaction, at room temperature in CH 2 Cl 2 for 4 h, to stop at the monosubstitution level.…”

Synthesis of imidazole and imidazolium porphyrins

“…Porphyrins with heterocyclic substitutions on the periphery have been utilized to form a variety of arrays and coordination modes to metal centers [1][2][3][4][5][6]. Specifically, imidazoles covalently attached to porphyrins have been used to form non-covalent arrays through the binding of an imidazole nitrogen to a metal inside of a second porphyrin [7][8][9][10][11][12][13].…”