A series of mono-, bis-, and tetrakisporphyrin assemblies was synthesized from 5-(p-pyridyl)-10,15,20-triphenylporphyrin, (pyPP)H-2, 5-(p-pyridyl)-10,15,20-tri(p-tolyl)porphyrin, (pyTP)H-2, (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)(2)Cl-2 with 2 equiv of the pyridyl porphyrins resulted in the formation of trans-bisporphyrin assemblies Pd[(pyPP)H-2]Cl-2, Pd[(pyTP)H-2]Cl-2(2), Pd[(pyPP)Zn]Cl-2(2), and Pd[(pyTP)Zn](?)2Cl(2). Treating cis-Pt(DMSO)(2)Cl-2 with 1 equiv of each pyridylporphyrin produced the cis-monoporphyrin complexes Pt(DMSO)-[(pyPP)H-2]Cl-2, Pt(DMSO)[(pyTP)H-2]Cl-2, Pt(DMSO)[(pyPP)Zn]Cl-2, and Pt(DMSO)[(pyTP)Zn]Cl-2. The treatment of Pt(DMSO)(pyPOR)Cl-2 with one more equiv of pyridylporphyrin resulted in the formation of cis-bisporphyrin assemblies, Pt[(pyPP)H-2]Cl-2(2), Pt[(pyTP)H-2]Cl-2(2), Pt[(pyPP)Zn]Cl-2(2), and Pt[(pyTP)Zn]Cl-2(2). Also, the reaction of Pt(DMSO)(pyPOR)Cl-2 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 as semblies [M(DPPP)[(pyPOR)H-2](2)]-(OTf)(2) and [M(DPPP)[(pyPOR)Zn](2)(OTf)(2). Synthesis of tetrakisporphyrin assemblies [M{(pyTP)H-2}(4)]X(2) (M = Pt, Pd; X = BF4, OTf) was accomplished by the reaction of [M(CH3CN)(4)]X(2) with (pyTP)H-2. Solution H-1 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)H-2}(2)](OTf)(2) was determined by single-crystal X-ray diffraction analysis (monoclinic, P2(1)/n, a 13.211(5) Angstrom, b = 36.741(19) Angstrom, c = 22.971(10) Angstrom, beta = 91.54(3)degrees, V = 11145.8(86) Angstrom(3), Z = 4, R = 8.21%, Rw = 18.44%).