A general preparative method for (tetratolylporphyrinato)titanium(II) η2-acetylene complexes, (TTP)Ti(η2-RCCR′), (R = R′ = CH3, CH2CH3, C6H5; R = CH3, R′ = CH2CH3) is described. Displacement of 2-butyne from (TTP)Ti(η2-MeCCMe) with terminal acetylenes allows the preparation of (TTP)Ti(η2-HCCH) and (TTP)Ti(η2-PhCCH). The π complexes undergo simple substitution reactions with pyridine (py) and 4-picoline (pic) to afford the bis(ligand) complexes trans-(TTP)Ti(py)2 and trans-(TTP)Ti(pic)2. The structure of the bis(picoline) complex, C66H56N4Ti, was determined by single-crystal X-ray diffraction (triclinic, P1̅, a = 9.764(2) Å, b = 10.899(2) Å, c = 13.530(2) Å, α = 92.18(2)°, β = 98.10(2)°, γ = 114.14(2)°, V= 1293.6(4) Å3, Z = 1, R = 5.2%, and Rw = 5.4%). Crystallographic symmetry requires that the Ti atom resides in the center of the 24 atom porphyrin plane. The Ti-Npic distance is 2.223(3) Å, and the average Ti-Npyrrole distance is 2.047(8) Å. The two picoline ligands are coplanar, and the dihedral angle formed by the plane of the picoline rings and the Ti-N1 vector is 43°. When (η2-PhCCPh)Ti(TTP) is treated with di-p-tolyldiazomethane, a diazo adduct (TTP)TiNNC(C6H4CH3)2 is formed. Atom transfer occurs when (η2-PhCCPh)Ti(TTP) is treated with XPPh3 (X = S, Se), resulting in a two-electron oxidized product, (TTP)Ti=X, PPh3, and free PhCsCPh. Treatment of (TTP)Ti(η2-PhCCPh) with elemental sulfur or selenium produces the perchalcogenido complexes (TTP)Ti(S2) and (TTP)Ti(Se2). The chalcogenide ligand complexes (TTP)TiS and (TTP)TiSe were also electrochemically characterized for comparison with related derivatives of (P)Ti(S2) and (P)Ti(Se2). Each compound undergoes two reversible one-electron reductions which are located at E1/2 = −1.07 ± 0.01 and 1.47 ± 0.01 V in CH2C12 containing 0.1 M tetra-n-butylammonium Perchlorate. They also undergo two oxidations, the first of which is irreversible, consistent with an electrode reaction involving the axial ligand rather than the porphyrin macrocycle. A comparison of potentials for oxidation of (TTP)TiX and (TPP)Ti(η2-X2) indicates a stronger titanium-chalcogen bond in the case of the terminal selenide and sulfide derivatives as compared to the metal-chalcogen bond in the η2-X2 complexes.