Matsuo Nonoyama

N-(2-Pyridyl)acetamide complexes of palladium(II), cobalt(II), nickel(II), and copper(II)

N-(2-Pyridyl)acetamide (aapH) complexes of palladium(II), cobalt(II), nickel(II), and copper(II) have been studied by means of magnetic susceptibilities, and infrared, electronic, and PMR spectra. In the octahedral complexes M(aapH)2X2(M = Co, Ni, Cu; X = Cl, Br, NCS, NO3), bidentate aapH is chelated through the pyridine-N and amid-O atomes, whereas in the square-planar Pd(aapH)2X2 (X = Cl, Br) unidentate aapH is coordinated through the pyridine-N atom alone. Under alkaline conditions aapH is deprotonated in the presence of palladium(II) to form Pd(aap)2·4H2O, aap being an anionic bidentate ligand and chelating through the pyridine-N and amide-O atoms.

Chelating C-metallation of N-phenylpyrazole with rhodium(III) and iridium(III)

Abstract Chelating C -metallation of N -phenylpyrazole(C 6 H 5 C 3 N 2 H 3 ) occurs with Rh III and Ir III to yield MX(C 6 H 4 C 3 N 2 H 3 ) 2 (M = Rh, X = Cl, Br; M = Ir, X = Cl), where it is coordinated through pyrazolyl 2-N and phenyl 1-C atoms to form a five-membered metallocycle. These complexes react with tri-n-butylphosphine (PBu 3 ) to give the adduct MX(C 6 H 4 C 3 N 2 H 3 ) 2 (PBu 3 ), which has an octahedral structure with trans -N,N, cis -C,C, and cis -X,PBu 3 donor sets. The ionic ethylenediamine complex Rh(C 6 H 4 C 3 N 2 H 3 ) 2 (en)Cl is also prepared.

Synthesis of binuclear copper(II) complexes with μ-oximado, μ-oxamato, and μ-oxalato-bridges

Abstract μ-Oximado, μ-oxamato, and μ-oxalato-bridged binuclear copper(II) complexes [Cu 2 (bridge)L 2 ] 2+ coordinated with another ligand (L) such as 2,2′-bipyridine, 2,2′-bipyridylamine, N,N,N′,N′-tetramethylethylenediamine. 2-(2-aminoethyl)pyridine, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N″,N″-tetraethyldiethylenetriamine, and N,N,N′,N″,N″-pentaethyldiethylenetriamine have been prepared and characterized by infrared and electronic spectra, and magnetic moments at room temperature. The complexes are square-planar or tetragonal octahedral for the bidentate L s, while they are five coordinate for the terdentate L s. The magnetic moments of these complexes depend upon the bridges as well as L s. The moments of the complexes with the bidentate L s are all subnormal and decrease in the order: μ-oxalato- > μ-oxamato- > μ-oxamido- bridge. The moments of the complexes with the terdentate L s are normal for a μ-oxalato-bridge but subnormal for a μ-oxamido-bridge. Magnetic copper-copper interaction seems to be more effective through a μ-oxamido bridge than through μ-oxamato- and μ-oxalato-bridges.

The bivalent nickel, cobalt, copper and palladium complexes of N-methyl derivatives of pyridine-2-carboxamide

Abstract Nickel(II), cobalt(II), copper(II) and palladium(II) complexes with pyridine-2-(N-methylcarboxamide)(abbreviated as mepiaH) and pyridine-2-(N,N-dimethylcarboxamide) (abbreviated as dimepia) as ligands were prepared and their properties and structures studied by spectroscopic and magnetic methods. With the former ligand, mepiaH, the 1:1(Cu), 1:2(Cu, Ni, Co), and 1:3(Ni, Co) complexes, and with the latter ligand, dimepia, 1:1(Cu), and 1:2(Cu, Ni, Co) complexes were obtained. Only with palladium a complex with the deprotonated ligand, Pd(mepia)22H2O was obtained. The structures of the 1:1 complexes are presumed to be square planar, and those of the 1:2 and 1:3 complexes to be distorted octahedral respectively.

Synthesis of copper(II) and nickel(II) complexes of several N-monosubstituted oxamide derivatives

Abstract Some nickel(II) and copper(II) complexes have been prepared with N-monosubstituted oxamide derivatives: HO(CH2)nNHCOCONH2 [n = 2(H3heo) and n = 3(H3hto)], 2-C5H4N-(CH2)n-NHCOCONH2[n = 1(H2pmo) and n = 2(H2peo)], and NH2COCONH(CH2)nNHCOCONH2 [n = 2(H4edo) and n = 3(H4(tdo)]. In the diamagnetic, square-planar Na2[Ni(Hheo)2]·H2O, Na2[Ni(Hhto)2]·2H2O, Na2[Ni(tdo)]·4H2O, and Na2[Ni(edo)], the bidentate Hheo and Hhto are coordinated via two deprotonated amide-N atoms without coordination of a terminal alcohol group and the quadridentate tdo and edo via all four deprotonated amide-N atoms. In [Cu(Hpmo)X]·mh2O and [Cu(Hpeo)X]·mH2O(X = Cl, Br) coordination atoms are pyridyl-N, primary amide-O, and deprotonated secondary amide-N atoms, while all the three nitrogen atoms of pmo are coordinated in Na[Cu(pmo)OH]·4H2O. The magnetically subnormal Na[Cu(hto)]·2H2O alone seems to be dimer bridged by an alkoxide-O atom.

Nickel(II), cobalt(II), cobalt(III) and copper(II) complexes of N-(2-picolyl)- and N-2(2′-pyridyl)ethyl-picolinamides

N-(2-picolyl)picolinamide(pmpH) and N-2-(2′-pyridyl) ethylpicolinamide(pepH) were synthesized and their complexes with nickel(II), cobalt(II), and copper(II) studied. The amide-hydrogen of pmpH disosciates readily in the presence of transition metal ions, and deprotonated pmp coordinates through the amide-nitrogen atom to metals. The dissociation of the amide-hydrogen of pepH is more difficult than that of pmpH and only in alkaline medium are complexes like Cu(pep)Cl and Co(pep)2ClO42/3H2O formed. The ligand pepH in the complexes M(pep)2X2 coordinates through the amide-ozygen atom. Copper perchlorate forms complexes in which both deprotonated pep (or pmp), and protonated pepH (or pmpH) are present as ligands.

DIRECT CYCLOAURATION OF 2-ANILINOPYRIDINE (HANP) WITH TETRACHLOROAURATE(III) AND THE X-RAY CRYSTAL STRUCTURE OF AUCL2(ANP)

Abstract 2-Anilinopyridine (Hanp) reacted with sodium tetrachloroaurate(III) in refluxing water directly to give cyclometallated [AuCl2(anp)], which was characterized spectroscopically and its structure determined by X-ray analysis. The metallation reaction involved direct activation of an ortho C H bond of the phenyl moiety and the deprotonated anionic ligand, anp, coordinated to Au through the pyridine-N and phenyl ortho-C atoms forming a six-membered chelate ring. Similarly cycloaurated complexes, [AuBr2(anp)] and [AuCl2(C N)] (CN = tlp, map, and tpm), were also prepared and characterized (Htlp= 2-(p-toluidino)pyridine, Hmap = 2-(N-methylanilino)pyridine, and Htpm= 2-(p-toluidino)-pyrimidine).

Cyclometallation of 2-(2-pyridyl)benzo[b]furan and1-(2-pyridyl and 2-pyrimidyl)indole with palladium(II)and rhodium(III). Structures of unexpectedly formed nitropalladium(II) complexes

Abstract Reactions of 2-(2-pyridyl)benzo[b]furan (Hpbf), 1-(2-pyridyl)indole(Hpyi) and 1-(2-pyrimidyl)indole (Hpmi) with palladium(II) acetate in refluxing acetonitrile resulted in the formation of unexpected nitro complexes, [Pd(NO2)L(CH3CN)](L=pbf, pyi and pmi). The presence of NO2 in the square planar dimethylsulfoxide(dmso) derivatives, [Pd(NO2)L(dmso)] (L=pbf and pyi) were confirmed by X-ray analysis. Palladation occurred at the C-3 of pbf and at the C-2 of pyi and pmi and a five member palladacycle was formed. The NO2 was coordinated trans to the pyridine-N atom and the dmso trans to the C atom through the O atom. Cyclorhodation of Hpbf, Hpyi and Hpmi with trichlorobis(tri-n-butylphosphine)rhodium(III) were similarly occurred inrefluxing toluene to afford octahedral complexes, [RhCl2L(PBu3)2],(PBu3=tri-n-butylphosphine). The octahedral structure of [RhCl2(pmi)(PBu3)2] was also determined by X-ray analysis. The two PBu3ligands were coordinated trans to each other and the strong trans influence of the σ-C donor atom stretched one Rh–Cl bond trans to it.

Bivalent metal complexes of N-(2-pyridylmethyl)-2-(ethylthio)acetamide

Abstract Nickel(II), palladium(II), platinum(II), and copper (II) complexes of N-(2-pyridylmethyl)-2-(ethylthio)acetamide (ptgH) have been studied. In the diamagnetic square-planar complexes [M(ptg)X]·nH2O (M = Pt, Pd, Ni) the amide group is coordinated through its deprotonated N atom, ptg being N,N,S-terdentate, while in the paramagnetic six-coordinated nickel complexes Ni(ptgH)2X2·2H2O the amide group is coordinated through its O atom, ptgH being N,O-bidentate. In the tetragonal copper complexes Cu(ptg)X·nH2O ptg acts similarly as in [M(ptg)X]·nH2O, the axial positions being occupied weakly by H2O molecules, whereas in the complexes Cu(ptgH)X2 the amide group exists in a rarely found iminol form, ptgH being, N,N,S-terdentate. Only the complex Cu(ptg) ClO4· 1 2 H2O shows a subnormal magnetic moment which may be due to copper-copper interaction through an amide group.

Double cyclopalladation ofN,N,N′,N′-tetramethylferrocene-1,1′-dicarbothioamide

Abstract A method was developed for one-pot synthesis of N,N N′,N′ -tetramethylferrocene-1,1′-dicarbothioamide (H 2 fdt); ferrocene was lithiated wit