Makoto Tadokoro - Academia.edu (original) (raw)

Papers by Makoto Tadokoro

Research paper thumbnail of Novel Building Blocks for Crystal Engineering: The First Synthesis of Oligo(imidazole)s

Research paper thumbnail of D3h-Symmetric Porphyrin-Based Rigid Macrocyclic Ligands for Multicofacial Multinuclear Complexes in a One-Nanometer-Sized Cavity

Chemistry - A European Journal, 2015

One-step synthesis of D3h symmetric cyclic porphyrin trimers 1 composed of three 2,2-(4,4-bisme... more One-step synthesis of D3h symmetric cyclic porphyrin trimers 1 composed of three 2,2-(4,4-bismethoxycarbonyl)bipyridyl moieties and three porphyrinatozinc moieties was achieved from a nickel-mediated reductive coupling of meso-5,15-bis(6-chloro-4methoxycarbonylpyrid-2-yl) porphyrinatozinc. Although the cyclic trimers 1 were obtained as a mixture that included other cyclic and acyclic porphyrin oligomers, an extremely specific separation was observed only for cyclic trimers 1 using silica gel columns modified with pyrenylethyl, cyanopropyl and other groups. Structural analysis of the cyclic trimers 1 was carried out using NMR spectroscopy and X-ray crystallography. Treatment of an  3-allylpalladium complex with a cyclic trimer gave a trispalladium complex containing three  3allylpalladium groups inside the space, indicating that the bipyridyl moieties inside the ring could work as bidentate metalloligands.

Research paper thumbnail of Heterodinuclear copper(II)-lead(II) and copper(II)-M(II) (M = manganese, iron, cobalt, nickel, copper, zinc) complexes of macrocycles with dissimilar 4- and 5-coordination sites: synthesis, structures, and properties

Inorganic Chemistry, 1993

Heterodinucleating macrocycles with two 2,6-bis(iminomethyl)-4-methylphenolate entities combined ... more Heterodinucleating macrocycles with two 2,6-bis(iminomethyl)-4-methylphenolate entities combined through two lateral chains,-(CH2)* and-(CH2),NH(CH2),,,-(m = 2,3), at the imino nitrogens have been prepared as CuIIPbII complexes of the formula [CuPb(L)]XY (L2-= L1 for m = 2 and L2 for m = 3; XY = (C104)2, (NOs)(PF6), (AcO)(BPh4)). [CuPb(Ll)](AcO)(BPh4).DMF crystallizes in the monoclinic crystal system, space group P21/n, w i t h Z = 4 , a = 18.890(3)A,b= 19.968(3)A,c= 12.704(2)A,fl=91.61(1)0,and V=4790(1) A3. Therefinement converges with R = 0.0697 and R, = 0.0863 for 4945 reflections with IFo[ > 3u(IFd). The crystal consists of a dimeric cation (cuPb(Ll)(A~)]2~+ bridged by acetate groups, tetraphenylborate ions, and DMF molecules. The Cu is located at the 4-coordination site formed with the ethylene chain and assumes a planar environment. The Pb is at the 5-coordination site formed with the-(CH2)2NH(CH&-chain and assumes an eight-coordinate structure also involving three acetate oxygen atoms. The Cu-Pb separation, bridged by two phenolic oxygens, is 3.577(2) A. In the crystal, the dimeric cations further interact through out-of-plane bonding between the (CuN202) entities forming a column along the a axis. The [CuPb(Ll)]XY complexes react with metal(I1) sulfates to form a series of CuI1M1I complexes, [CuM(LI)]XY (M = Mn, Fe, Co, Ni, Cu, Zn). [CuMn(Ll)](AcO)(BPh4) crystallizes in the monoclinic space group P21/n, with Z = 4, a = 17.508(8) A, b = 15.539(5) A, c = 16.515(5) A, fl = 106.30(3)O, and V = 4312(3) A3. The refinement converges with R = 0.0689 and Rw = 0.0563 for 2935 reflections with IFd > 3u(IFol). The Cu(I1) and Mn(I1) ions reside at the 4-and 5-coordination sites of the macrocycle, respectively, and the acetate group bridges the two metal ions providing a nearly square-pyramidal geometry for the Cu and a highly distorted six-coordinate environment for the Mn. The Cu-Mn separation is 3.122(2) A. The cryomagnetic investigations (4.2-300 K) for the CuMn, CuFe, CuCo, CuNi, and CuCu complexes reveal the operation of an antiferromagnetic spin-exchange interaction within each molecule. The cyclicvoltammograms of the CUM complexes show Cu(II)/Cu(I) reduction near-0.8 V (vs SCE) and oxidation at the ligand center near +1.3 V. The oxidation of the Fe(I1) of the CuFe complex occurs at +0.64 V whereas the Mn(I1) ion of the CuMn complex and the Co(I1) ion of the CuCo complex are hardly oxidized.

Research paper thumbnail of Novel Building Blocks for Crystal Engineering: The First Synthesis of Oligo(imidazole)s

Research paper thumbnail of D3h-Symmetric Porphyrin-Based Rigid Macrocyclic Ligands for Multicofacial Multinuclear Complexes in a One-Nanometer-Sized Cavity

Chemistry - A European Journal, 2015

One-step synthesis of D3h symmetric cyclic porphyrin trimers 1 composed of three 2,2-(4,4-bisme... more One-step synthesis of D3h symmetric cyclic porphyrin trimers 1 composed of three 2,2-(4,4-bismethoxycarbonyl)bipyridyl moieties and three porphyrinatozinc moieties was achieved from a nickel-mediated reductive coupling of meso-5,15-bis(6-chloro-4methoxycarbonylpyrid-2-yl) porphyrinatozinc. Although the cyclic trimers 1 were obtained as a mixture that included other cyclic and acyclic porphyrin oligomers, an extremely specific separation was observed only for cyclic trimers 1 using silica gel columns modified with pyrenylethyl, cyanopropyl and other groups. Structural analysis of the cyclic trimers 1 was carried out using NMR spectroscopy and X-ray crystallography. Treatment of an  3-allylpalladium complex with a cyclic trimer gave a trispalladium complex containing three  3allylpalladium groups inside the space, indicating that the bipyridyl moieties inside the ring could work as bidentate metalloligands.

Research paper thumbnail of Heterodinuclear copper(II)-lead(II) and copper(II)-M(II) (M = manganese, iron, cobalt, nickel, copper, zinc) complexes of macrocycles with dissimilar 4- and 5-coordination sites: synthesis, structures, and properties

Inorganic Chemistry, 1993

Heterodinucleating macrocycles with two 2,6-bis(iminomethyl)-4-methylphenolate entities combined ... more Heterodinucleating macrocycles with two 2,6-bis(iminomethyl)-4-methylphenolate entities combined through two lateral chains,-(CH2)* and-(CH2),NH(CH2),,,-(m = 2,3), at the imino nitrogens have been prepared as CuIIPbII complexes of the formula [CuPb(L)]XY (L2-= L1 for m = 2 and L2 for m = 3; XY = (C104)2, (NOs)(PF6), (AcO)(BPh4)). [CuPb(Ll)](AcO)(BPh4).DMF crystallizes in the monoclinic crystal system, space group P21/n, w i t h Z = 4 , a = 18.890(3)A,b= 19.968(3)A,c= 12.704(2)A,fl=91.61(1)0,and V=4790(1) A3. Therefinement converges with R = 0.0697 and R, = 0.0863 for 4945 reflections with IFo[ > 3u(IFd). The crystal consists of a dimeric cation (cuPb(Ll)(A~)]2~+ bridged by acetate groups, tetraphenylborate ions, and DMF molecules. The Cu is located at the 4-coordination site formed with the ethylene chain and assumes a planar environment. The Pb is at the 5-coordination site formed with the-(CH2)2NH(CH&-chain and assumes an eight-coordinate structure also involving three acetate oxygen atoms. The Cu-Pb separation, bridged by two phenolic oxygens, is 3.577(2) A. In the crystal, the dimeric cations further interact through out-of-plane bonding between the (CuN202) entities forming a column along the a axis. The [CuPb(Ll)]XY complexes react with metal(I1) sulfates to form a series of CuI1M1I complexes, [CuM(LI)]XY (M = Mn, Fe, Co, Ni, Cu, Zn). [CuMn(Ll)](AcO)(BPh4) crystallizes in the monoclinic space group P21/n, with Z = 4, a = 17.508(8) A, b = 15.539(5) A, c = 16.515(5) A, fl = 106.30(3)O, and V = 4312(3) A3. The refinement converges with R = 0.0689 and Rw = 0.0563 for 2935 reflections with IFd > 3u(IFol). The Cu(I1) and Mn(I1) ions reside at the 4-and 5-coordination sites of the macrocycle, respectively, and the acetate group bridges the two metal ions providing a nearly square-pyramidal geometry for the Cu and a highly distorted six-coordinate environment for the Mn. The Cu-Mn separation is 3.122(2) A. The cryomagnetic investigations (4.2-300 K) for the CuMn, CuFe, CuCo, CuNi, and CuCu complexes reveal the operation of an antiferromagnetic spin-exchange interaction within each molecule. The cyclicvoltammograms of the CUM complexes show Cu(II)/Cu(I) reduction near-0.8 V (vs SCE) and oxidation at the ligand center near +1.3 V. The oxidation of the Fe(I1) of the CuFe complex occurs at +0.64 V whereas the Mn(I1) ion of the CuMn complex and the Co(I1) ion of the CuCo complex are hardly oxidized.