Hidetaka Yuge

Different co-ordination behaviour of 1,2-diaminoethane (en) and tetracyanonickelate(II) upon accommodation of polar guest molecules in their metal complex hosts: crystal structures of [M(en)2Ni(CN)4]·2PhNH2(M = Ni, Cu, Zn or Cd) and [{Cd(en)}2(en){Ni(CN)4}2]·4PhOH

The single-crystal structures have been determined for aniline and phenol clathrates. Aniline clathrates [M(en)2Ni(CN)4]·2PhNH2(M = Ni, Cu, Zn or Cd; en = 1,2-diaminoethane) are isomorphous, having monoclinic space group P21/c(Z= 2). The unit cell parameters a, b, c and β, and R index for the reflections used are: M = Ni, 9.452(3), 10.125(3), 13.440(3)A and 107.27(2)°, 0.0443 for 1806; for M = Cu, 9.547(4), 10.621(5), 12.746(3)A and 107.89(2)°, 0.0635 for 1861; for M = Zn, 9.550(3), 10.407(2), 13.026(2)A and 107.50(1)°, 0.0513 for 1758; and for M = Cd, 9.924(2), 10.545(3), 12.510(1)A and 107.63(1)° 0.0456 for 1829. The guest PhNH2 molecules are accommodated among [–M(en)2–NC–Ni(CN)2–CN–]n chains extending along the b axis. The bis(en)-chelated M atoms are linked with trans-di-µ-cyano-dicyanonickelate(II) moieties alternately, and adopt an elongated octahedral configuration along the chain. The phenol clathrate [{Cd(en)}2(en){Ni(CN)4}2]·4PhOH belongs to the triclinic system, space group P, with a= 11.868(1), b= 13.030(1), c= 7.7113(6)A, α= 105.956(7), β= 94.951(8), γ= 91.584(9)°, Z= 1 and R= 0.0410 for 4095 reflections. Three kinds of crystallographically independent PhOH molecules are enclathrated in the three-dimensional host framework in which the en-chelated Cd atoms are linked with infinite [〉Ni〈(CN–Cd–NC–)2]n chains and Cd–NC–Ni(CN)2–CN–Cd and Cd–en–Cd bridges. Interhost, interguest and host–guest hydrogen-bond formation stabilize the whole crystal structures, which are compared with those of [M(en)2Ni(CN)4] complexes and the [Cd(en)Ni(CN)4]·2C6H6 clathrate.

Synthesis and structure of tris[(2-alkoxymethyl)phenyl]germanes and tris[(2-methylthiomethyl)phenyl]germane

Abstract Tris[(2-alkoxymethyl)phenyl]germanes and tris[(2-methylthiomethyl)phenyl]germane were prepared and their structures were investigated by means of X-ray crystallographic analysis and 73Ge NMR spectra, which indicated incipient dative bonding between germanium and sulfur or oxygen atoms to make the germanium atom hexavalent and heptavalent, respectively.

Hofmann-H2O-type and Hofmann-H2O-Td-type host structures accomodating 1,4-dioxane: crystal structures of trans-bis (morpholine-N) cadmium(II) tetracyanonickelate(II), trans-diaquacadmium(II) tetracyanonickelate(II)-(1,4-dioxane)() and trans-diaquacadmium(II) tetracyanocadmate(II) (1,4-dioxane)()

Abstract In order to stabilise six-membered alicyclic ether guests through a hydrogen bond with an H2O ligand in the host, Hofmann-H2O-type [Cd(H2O)2Ni(CN)4] and Hofmann-H2O-Td-type [Cd(H2O)2Cd(CN)4] hosts were examined for accomodating 1,4-dioxane and morpholine as probable guests. The single crystal structures of the eventually obtained morpholine-ligated complex [Cd(C4H9NO)2Ni(CN)4] (1) and 1,4-dioxane-guest clathrates, [Cd(H2O)2Ni(CN)4]·2C4H8O2 (2) and [Cd(H2O)2Cd(CN)4]·2C4 H8O2 (3), are closely related in topology with previously known [Cd(py)2Ni(CN)4], [Cd(NH3)2Ni(CN)4]·2C4H8O2 and [Cd(NH3)2Cd(CN)4] ·2C6H6, respectively, but involve hydrogen bonds between the morpholine ligands in 1, and between the aqua ligand of the host and the guest 1,4-dioxane in 2 and 3. Complex 1 crystallises in the orthorhombic system, Pmna, a = 7.985(1), b = 6.695(2), c = 14.314(2) A , Z = 2, R = 0.048 for 1240 reflections; clathrate 2: monoclinic, P2/m, a = 7.3980(8), b = 7.6454(6), c = 8.0639(9) A , β = 93.703(9)°, Z = 1, R = 0.041 for 1040; 3: monoclinic, C2/c, a = 12.054(5), b = 11.334(6), c = 15.249(2) A , β = 91.62(2)°, Z = 4, R = 0.043 for 2129. The structure of a Hofmann-H2O-type hydrate [Fe(H2O)2Ni(CN)4]·4H2O, orthorhombic Pnma, a = 12.200(2), b = 14.028(2), c = 7.2327(9) A , Z = 4, R = 0.042 for 710, is also reported.

Three Polymorphic CdII Coordination Polymers Obtained from the Solution and Mechanochemical Reactions of 3‐Cyanopentane‐2,4‐dione with CdII Acetate

We previously reported that monomeric and polymeric metal complexes are obtained from solution and mechanochemical reactions of 3-cyano-pentane-2,4-dione (CNacacH) with 3d metal acetates (M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)). A common feature found in all complexes was that their structural base is trans-[M(CNacac)(2)]. Here, we report that the reactions of CNacacH with Cd(II) acetate in the solution and solid states afford different coordination polymers composed of trans-[Cd(CNacac)(2)] and cis-[Cd(CNacac)(2)] units, respectively. From a methanol solution containing CNacacH (L) and Cd(OAc)(2)⋅2 H(2)O (M), a coordination polymer (Cd-1) in which trans-[Cd(CNacac)(2)] units are three-dimensionally linked was obtained. In contrast, two different coordination polymers, Cd-2 and Cd-3, were obtained from mechanochemical reactions of CNacacH with Cd(OAc)(2)⋅2 H(2)O at M/L ratios of 1:1 and 1:2, respectively. In Cd-2, cis-[Cd(CNacac)(2)] units are two-dimensionally linked, whereas the units are linked three-dimensionally in Cd-3. Furthermore, Cd-1 and Cd-2 converted to Cd-3 by applying an annealing treatment and grinding with a small amount of liquid, respectively, in spite of the polymeric structures. These phenomena, 1) different structures are formed from solution and mechanochemical reactions, 2) two polymorphs are formed depending on the M/L ratio, and 3) structural transformation of resulting polymeric structures, indicate the usability of mechanochemical method in the syntheses of coordination polymers as well as the peculiar structural flexibility of cadmium-CNacac polymers.

Bis(3-cyano-pentane-2,4-dionato) Co(II) as a linear building block for coordination polymers: combinations with two polypyridines

Two types of bis(β-diketonato) Co(II) complexes, [Co(CNacac)2] (CNacac = 3-cyano-pentane-2,4-dionato), and [Co(dbm)2] (dbm = dibenzoylmethanato or 1,3-diphenyl-propane-1,3-dionato) were examined as linear building blocks for the construction of coordination polymers in combination with two oligopyridines, 1,4-bis(4,2’:6’,4”-terpyridin-4’-yl)benzene (L1) and 1,3-bis(3,2’:6’,3”-terpyridin-4’-yl)benzene) (L2). From combinations of [Co(CNacac)2] with L1 and L2, 2-D coordination polymers, [Co(CNacac)2]2(L1)·(CHCl3)·(CH3OH) (CoCN-1) and [Co(CNacac)2](L2)1/2·(tetrachloroethane)3/2 (CoCN-2), are obtained. Both CoCN-1 and CoCN-2 have 2D (4,4) net structures, in which L1 and L2 are tetradentate. In contrast, combination of [Co(dbm)2] with L2 affords a 1-D coordination polymer, [Co(dbm)2](L2)·4(CH3OH) (Codbm-1), in which L2 is bidentate. L2 as a tetradentate ligand was inhibited by bulky phenyl rings in [Co(dbm)2]. These results indicate that [Co(CNacac)2] with a relatively simplified structure is useful as a linear building block in combinations with bulky oligopyridines.

Cyano-linked structures in polymeric cadmium cyanide-pyridine (py) and -isoquinoline (iquin) complexes : crystal structures of [Cd(py)2][Cd(CN)4], [{Cd(CN)(py)2}3][Cd2(CN)7] and [Cd(iquin)2][Cd(CN)3(iquin)2]2

Crystal structures of two pyridine (py)- and one isoquinoline (iquin)-ligated cadmium(II) poly(cyano)-cadmate(II) complexes, [Cd(py)2][Cd(CN)4]1, [{Cd(CN)(py)2}3][Cd2(CN)7]2 and [Cd(iquin)2][Cd(CN)3(iquin)2]23 have been determined from single-crystal X-ray diffraction data; 1: orthorhombic Cccm, a= 9.386(2), b= 14.358(2), c= 14.439(2)A, Z= 4; 2: trigonal Rc, a=b= 13.987(2) and c= 43.769(8)A(hexagonal setting), Z= 6; and 3: (L) monoclinic P21/c, a= 8.178(2), b= 20.557(2), c= 16.244(3)A, β= 97.20(2)°, Z= 2. Although they all have the composition of a base adduct of Cd(CN)2, the structures are completely different from one another. Complex 1[i.e. Cd(CN)2·L] has a three-dimensional framework built of an alternate array of tetrahedral [Cd(CN)4]2– and octahedral Cd2+ to which a pair of pyridine ligands ligate at the trans positions. The three-dimensional structure of complex 2[i.e. 5Cd(CN)2·6L] is comprised of a trimeric assembly [{Cd(CN)(py)2}3]3+ and a dimeric condensate [(NC)3Cd(CN)Cd(CN)3]3– linked alternately by cyano bridges extending from the latter. A one-dimensional extension of the meshed chain is seen in the structure of complex 3[i.e. Cd(CN)2·2L], where two kinds of trans-[Cd(iquin)2] moieties, one in an octahedral (Cdoct) and the other in a trigonal-bipyramidal (Cdtbpy) co-ordination, are combined with the equatorial CN groups in a 1 : 2 ratio Cdoct:Cdtbpy. The bulkiness of the aromatic base appears to affect the mode of cyanide linkage in these structures.

Novel negatively charged cyanocuprate(I) host [Cu4(CN)7]3− built of tetrahedral Cu(I) coordination centers: Crystal structure of [{NH2(CH2CH2)2NCH2CH2NH2}2H][Cu4(CN)7]

The title inclusion compound [{NH2(CH2CH2)2NCH2CH2NH2}2H][Cu4(CN)7] was obtained as single crystals from an aqueous solution containing CuCN, KCN, andN-(2-aminoethyl)piperazine. It crystallizes in the monoclinic space groupP2/n,a = 12.3829(9),b = 8.5970(9),c = 12.6633(7) Å, β = 109.984(5)°,z = 2,R = 0.035 for 2921 independent reflections. The inclusion structure is composed of the hydrogen-bonded dimeric onium guest [{NH2(CH2CH2)2NCH2CH2NH2}2H]3+ and the negatively-charged three-dimensional host [CU4(CN)7]3− in which the CN-bridged framework Cu(I) atoms are all tetrahedral. A polyacene-like one-dimensional array of hexagons cornered by Cu(I) atoms and edged by -CN- linkages is arrayed in parallel to theb axis and stacked approximately along the c axis. The Cu(I) corner shared in the one-dimensional array extends an N-coordinate CN group along the c axis to a pair of unshared Cu(I) corners for which the C end behaves as a bifurcated ligand to build up the three-dimensional host structure. The cavity is composed of two networks of the hexagons at the top and bottom and pillared by six >CN- groups and accommodates a dimeric guest ofN-(2-aminoethyl)piperazinium cations protonated at each 4-N with the cations being hydrogen-bonded to each other through the 2-NH2 groups sharing another H+.

Steric influence on platinum(II) ascorbate complexes

From the reaction between dihydroxoplatinum(II) and l-ascorbic acid, two types of platinum(II) ascorbate complexes were obtained and structurally characterized with ethylenediamine (en), N,N-dimethylethylenediamine (dmen) and N,N,N′-trimethylethylenediamine (trimen) as stabilizing ligands. In [Pt(en)(asc-C,O)] (1), [Pt(dmen)(asc-C,O)] (2) and [Pt(trimen)(asc-C,O)] (4), the ascorbate dianion forms a five-membered chelate ring, coordinating to the Pt(II) ion at the 2-carbon and the 5-oxygen atoms (C,O-chelate). From the same mother solution, crystals of [Pt(trimen)(asc-O,O′)] (3) were obtained during the precipitation of 4; in 3 the ascorbate is bound to the Pt at the 2- and 3-oxygen atoms (O,O′-chelate). Compounds 3 and 4 are the first well-characterized linkage isomers among the transition-metal ascorbate complexes. The O,O′-chelated 3 slowly changes to the C,O-chelated 4 in an aqueous solution. Bulkiness of the stabilizing ligand, i.e. en, dmen and trimen has an influence on the formation of the C,O-chelated species, 1, 2 and 4.

A phosphane analog of nedaplatin: preparation and structural characterization of cis-bis(trimethylphosphane)-(glycolato-O,O′)platinum(II)

Abstract A water-soluble cis -bis(phosphane)platinum(II) complex, cis -[bis(trimethylphosphane) (glycolato- O , O ′)platinum(II)] ( 1 ), was crystallized from an organic solvent as a hemihydrate, [Pt(PMe 3 ) 2 (OCH 2 COO)]·0.5H 2 O ( 1 ·0.5H 2 O), which is an analog of the anticancer drug nedaplatin, [Pt(NH 3 )) 2 (OCH 2 COO)] ( 1′ ). Crystal data at 160(5) K are: C 8 H 21 O 3.5 P 2 Pt, monoclinic, P 2 t (No. 4), a = 9.012(3), b = 9.824(7), c = 15.417(3) A, β = 97.92(2)°, U = 1351.8(11) A 3 , Z = 4; those measured at 293(2) K are: a = 9.066(2), b = 9.948(2), c = 15.525(1) A , β = 97.40(1)°, U = 1388.5(4) A 3 . The glycolate dianion forms a five-membered chelate ring, coordinating to the Pt(II) ion not only at an O atom of the carboxyl group but also at the hydroxy. The NMR spectra show that the hydroxy group ligates to the Pt(II) in the solution of organic solvents as well as in the crystalline state, but that it exchanges with a water molecule in aqueous solution.

Mineralomimetic chemistry as a modern aspect of co-ordination chemistry

By denoting as mineralomimetic chemistry the chemistry of the build-up of mineral-like structures using materials that never give stable minerals in nature, the multidimensional structures comprised of the linkage of co-ordination polyhedra such as those observed for natural minerals are demonstrated for the products obtained by the crystal engineering strategy based on the structural similarity between Cd(CN)2 and SiO2, and between Cd(CN)4 and SiO4. The structures of high-cristobalite, low-cristobalite, high-tridymite, stishovite, pyrosilicate, chain silicates, ring silicates, layer silicates, framework silicates, etc. have been mimicked by polymeric complexes of cadmium cyanide and polycyanopolycadmate(II); [H3(H2O)14][Cd{Cu2(CN)7}] has a doubly interpenetrating structure of the pyrite-mimetic [Cd{Cu2(CN)7}] framework and the framework of the hydrogen-bonded water molecules has a topology approximated to that of rutile; a two-dimensional ice structure (comparable with the two-dimensional array of the water molecules in ice Ih) is built from aqua ligands and the intercalated waters in [Cd(H2O)2Ni(CN)4]·4H2O. As a modern aspect of co-ordination chemistry, the concept of mineralomimetic chemistry is extended more generally for the multidimensional structures built from the linkage of co-ordination polyhedra.