150392-79-3Relevant academic research and scientific papers
Facile Syntheses of Titanium(II), Tin(II), and Vanadium(II) Porphyrin Complexes through Homogeneous Reduction. Reactivity of trans-(TTP)TiL2 (L = THF, t-BuNC)
Wang, Xiaotai,Gray, Steve D.,Chen, Jinyuan,Woo, L. Keith
, p. 5 - 9 (2008/10/08)
Facile syntheses of the meso-tetra-p-tolylporphyrin (TTP) complexes trans-(TTP)Ti(THF)2 (1), (TTP)Sn (2), and trans-(TTP)V(THF)2 (3) are achieved through homogeneous reduction of high-valent precursors using NaBEt3H. The composition of the new compound trans-(TTP)Ti(THF)2 was determined by spectroscopic and chemical characterization. Ligand displacement reactions of trans-(TTP)Ti(THF)2 with t-BuNC produced a new Ti(II) complex, trans-(TTP)Ti(t-BuNC)2. The ligand-binding preference of (TTP)TiIILn (n = 1, 2) is picoline ～pyridine > t-BuNC > PhC≡CPh > EtC≡CEt > THF.
Synthesis, characterization, substitution, and atom-transfer reactions of (n2-alkyne)(tetratolylporphyrinato)titanium(II). X-ray structure of trans-bis(4-picoline)(tetratolylporphyrinato)titanium(II)
Woo, L. Keith,Hays, J. Alan,Young Jr., Victor G.,Day, Catherine L.,Caron, Cecile,D'Souza, Francis,Kadish, Karl M.
, p. 4186 - 4192 (2008/10/08)
A general preparative method for (tetratolylporphyrinato)titanium(II) η2-acetylene complexes, (TTP)Ti(η2-RC≡CR′), (R = R′ = CH3, CH2CH3, C6H5; R = CH3, R′ = CH2CH3) is described. Displacement of 2-butyne from (TTP)Ti(η2-MeG≡CMe) with terminal acetylenes allows the preparation of (TTP)Ti(η2-HC≡CH) and (TTP)Ti(η2-PnC≡CH). 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, P1, a = 9.764(2) A?, b = 10.899(2) A?, c = 13.530(2) A?, α = 92.18(2)?, β = 98.10(2)°, γ = 114.14(2)°, V = 1293.6(4) A?3, 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) A?, and the average Ti-Npyrrole distance is 2.047(8) A?. 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-PhC≡CPh)Ti(TTP) is treated with di-p-tolyldiazomethane, a diazo adduct (TTP)Ti=NN=C(C6H4CH3)2 is formed. Atom transfer occurs when (η2-PhC≡CPh)Ti(TTP) is treated with X=PPh3 (X = S, Se), resulting in a two-electron oxidized product, (TTP)Ti=X, PPh3, and free PhC≡CPh. Treatment of (TTP)Ti(η2-PhC≡CPh) with elemental sulfur or selenium produces the perchalcogenido complexes (TTP)Ti(S2) and (TTP)Ti(Se2). The chalcogenide ligand complexes (TTP)Ti=S and (TTP)Ti=Se 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 CH2Cl2 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)Ti=X 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.
