Keiko Miyamoto

Crystal structure of trans-diacetonitritrile(diaqua)(N,N,N',N'-tetramethylethylenediamine) nickel(II)dibromide tetrahydrate, [Ni(tmen)(CH3CN)2(H2O)2]2+·2Br–·4H2O, C10H34Br2N4NiO6

Abstract C10H34Br2N4NiO6, monoclinic, C2/c (no. 15), a = 19.062(4) Å, b = 8.106(2) Å, c = 15.484(3) Å, β = 112.96(3)°, V = 2203.0(9) Å3, Z = 4, Rgt(F) = 0.0348, wRref(F2) = 0.0405, T = 273.2 K.

Crystal structure of ethanolato-dibenzoylmethanato-(R,R-dibenzoylstilbenediamine)-nitratonickel(II), Ni(C2H5OH)(C15H11O2)(C28H26N2)(NO3)

C45H43N3NiO6, monoclinic, P1211 (no. 4), a = 12.115(2) Å, b = 13.496(2) Å, c = 12.524(2) Å, ) = 96.008(2)°, V = 2036.5 Å, Z = 2, Rgt(F) = 0.062, wRref(F) = 0.063, T = 273 K. Source of material The title compound was prepared by adding 0.393 g of dibenzoylstilbenediamine (dbstien) obtained according to the published method [1] to 0.291 g of Ni(NO3)2 · 6H2O dissolved in 10 ml of ethanol followed by the addition of 0.224 g of dibenzoylmethane and 0.07 g of KOH, and stirred for 60 minutes. The resulting bluish-green solution was filtered, allowed to stand. Green crystals suitable for X-ray diffraction experiments were obtained by slow vapour diffusion of diethyl ether into the ethanol solution. Experimental details The hydrogen atoms bound to carbon atoms were fixed at calculated positions with d(C—H) = 0.97 Å, d(C=C—H) = 1.08 Å. The hydrogen bound to O6 was not located in the difference Fourier map due to the probable disorder over two sites. Discussion Stilbenediamine containing metal complexes of copper, nickel and zinc have been catching attention due to their catalytic activity in asymmetric syntheses [2-9]. Recently a chiral copper catalyst having dibenzoylstilbene as its ligand has been developed to achieve enantioselective Mannich-type reactions of Nacylimino esters with, for example, alkyl vinyl ethers to afford the corresponding N-acylated amino acid derivatives [7]. To date, only a few structures of these complexes have been reported, hence our interest to isolate, crystallize and to determine the molecular structure of the nickel complex presented here. The crystal structure consists of asymmetric units containing one Ni complex, [Ni(C2H6O)(C15H11O2)(C28H28N2)(NO3)]. The central nickel atom has a slightly distorted octahedral coordination, with the angles around nickel ranging from 81.9(2)° to 103.1(2)°, and 172.8(2)° to 177.1(2)°, respectively. The average Ni—N distance (Ni—N2, Ni—N3) is 2.091(5) Å, which is in the normal bond range for an octahedral Ni complex. The respective Ni—Odbm distances Ni—O4 and Ni—O5 are 1.976(4) Å and 2.033(4) Å which reflect the relative trans effect exhibited by N3 as opposed to O6 (ethanol), making the former distance shorter. The nitrate molecule coordinates Ni at the expected distance Ni—O1 of 2.179(4) Å. The dibenzoylstilbene and dibenzoylmethanate (dbm) bidentate chelate planes are virtually perpendicular to each other. The atomic arrangement around atoms C16 and C17 reflects the R,R configuration of dibenzoylstilbene of the overall absolute molecular structure. Finally, the oxygen of the ethanol molecule locates at the normal distance of 2.083(4) Å from the nickel centre. Z. Kristallogr. NCS 225 (2010) 161-163 / DOI 10.1524/ncrs.2010.0070 161

Crystal structure of aqua(benzoylacetonato)(R,R-dibenzylstilbene-diamine)( nitrato)nickel(II) ethanol disolvate, Ni(H2O)(C10H10O2)(C28H28N2)(NO3) · 1.9C2H5OH

C41.82H48.43N3NiO7.91, orthorhombic, P212121 (no. 19), a = 13.491(1) Å, b = 14.260(1) Å, c = 21.430(2) Å, V = 4122.7 Å, Z = 4, Rgt(F) = 0.050, wRref(F) = 0.053, T = 273 K. Source of material The title compound was prepared by adding 0.393 g of dibenzylstilbenediamine (dbstien) obtained according to the published method [1] to 0.291 g ofNi(NO3)2 · 6H2O dissolved in 3ml of ethanol followed by addition of 0.162 g of benzoylacetone.Themixture was heated with stirring for 30 minutes. The resulting bluish green solutionwas allowed to stand overnight.The crude crystals obtained were recrystallized from an acetone/ethanol mixture via vapor diffusion using diethyl ether to yield green single crystals. Discussion Metal complexes of copper, nickel and zinc containing a stilbenediamine as a chiral ligand have been catching attention due to their catalytic activity in asymmetric syntheses [1-6].Recently a chiral copper catalyst having dibenzylstilbene as its ligand has been developed to achieve enantioselective Mannich-type reactions of N-acylimino esters with, for example, alkyl vinyl ethers to afford the correspondingN-acylated amino acid derivatives [4].To date, only a few crystal structures of these complexes have been reported, hence our interest to isolate, crystallize and to determine the molecular structure of the nickel complex presented here. The asymmetric unit of the crystal structure consists of one Ni complex and two ethanolmolecules (figure, top, 30%probability ellipsoids). The central nickel atom has a slightly distorted octahedral coordination, with the angles on nickel ranging from 85.6(2)° to 98.9(3)°, and 173.0(2)° to 178.2(2)°, respectively. The averageNi—Ndistance (Ni—N1,Ni—N2) is 2.108(7)Å, which is in the normal range for octahedralNi complexes.TheNi—O(bzac) distancesNi—O1 andNi—O2 of 2.030(5)Å and 1.986(5)Å, respectively, reflect the relative trans effect exhibited byN2 as opposed to O6, making the latter distance shorter. The nitrate ion coordinates at the expected distance,Ni—O3, of 2.202(5)Å. The dibenzylstilbene and bzac bidentate chelate planes are virtually perpendicular to each other. The dihedral angle between the least square planes (C26,C31) and (C33,C38), is 24.12°, while the angle between the planes (C14,C31) and (C20,C25) is 78.0(7)°, which is much larger than expected from a more symmetrical placement of the four phenyl groups of dibenzylstilbene. In fact, the phenyl (C14,C19), lines upwith bzac phenyl (C4,C9)with a respective dihedral angle of 4.5(8)°, but out of range for intra &stacking. The atomic arrangement about C11 and C12 reflects the R,R configuration of dibenzylstilbene of the overall absolute molecular structure. Finally, the oxygen of water molecule locates at the distance of 2.057(5)Å from the nickel. The two ethanol molecules are involved in an intermolecular hydrogen bonding network with the nickel complex and themselves (figure, bottom). More specifically, O7 from the first ethanol hydrogen bonds to H1 of O6(water), whileO8 of the second ethanol hydrogen bonds toH43 ofO7, andO3(nitro) in turn hydrogenbonds toH49ofO8, at the respective O···O distances of 2.72(1) Å, 2.78(1) Å, and 2.85(1) Å. The occupancy factor of the second ethanolmolecule was refined to 0.905 presumably because of evaporation of themolecule from the crystal. Z. Kristallogr. NCS 222 (2007) 243-245 / DOI 10.1524/ncrs.2007.0102 243

Crystal structure of μ3-chloro-μ3-hydroxo-tris(μ-chloro)tris(tetramethylethylenediamine) trinickel(II) triiodide, [Ni3(C6H16N2)3Cl4(OH)][I3]

Abstract C18H49Cl4I3N6Ni3O, triclinic, P1̅ (no. 2), a = 15.371(3) Å, b = 11.777(2) Å, c = 11.505(2) Å, α = 96.075(7)°, β = 84.816(6)°, ϒ = 111.562(6)°, V = 1923.1 Å3, Z = 2, Rgt(F) = 0.061, wRref(F) = 0.065, T = 273 K.