Synthesis and Structural Characterization of a New Cadmium(II) Complex with a Double Betaine

A new flexible double betaine L （L = 1,4-bis（pyridinio-4-carboxylato-N-methyl）benzene, C20H16N2O4） and its cadmium（Ⅱ） complex [Cd（H2O）aL（NO3）]NO3.H2O 1 were synthesized. Complex 1 was obtained by self-assembly reaction of [Cd（NO3）2]-4H2O and L in hot water,and its crystal structure was determined by single-crystal X-ray diffraction analysis. Crystallographic data for complex 1： C20H24CdN4O14.H2O, Mr = 674.85, monoclinic, space group P21/c, a =13.7854（3）, b = 14.2820（3）, c = 14.9188（4） ,A°, β = 116.418（1）°, V = 2630.5（1）A°^3, Z = 4, Dc= 1.704g/cm^3,/J（MoKα） = 0.911 mm^-1, F（000） = 1368, the final R = 0.0315 and wR = 0.0768 for 3637 observed reflections with I 〉 2σ（I）. In complex 1, L acts as a monodentate ligand to link a Cd（Ⅱ） ion in a novel coordination mode of double betaines. The mononuclear [Cd（H2O）aL（NO3）] units are connected through intermolecular hydrogen bonds and π-π stacking reactions to generate a 3D network.

Characterization and Crystal Structures of Two Copper(Ⅱ) Complexes Constructed by a Flexible Double Betaine Ligand

A flexible double betaine 1,4-bis（pyridinil-4-carboxylato）-1,4-dimethylbenzene L has been used to generate two Cu（Ⅱ）-containing metal complexes that exhibit different polymeric structures： [Cu（H2O）2 L].2NO3 1 and [Cu（H2O）3 L].2Cl.H2O 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1： triclinic, space group PT, a = 5.253（2）, b = 7.406（3）, c = 14.792（5） A, α = 84.195（5）, β = 80.014（5）, γ = 78.053（5）°, V= 553.2（3）A^3, Z = 1, F（000） = 293, Dc = 1.717 g/cm^3, the final R = 0.0385 and wR = 0.1079 for 1883 observed reflections （I 〉 2σ（I））; and those for 2： monoclinic, space group P21/c, a = 10.222（3）, b = 25.287（7）, c = 9.277（3）A, β = 93.572（5）°, V = 2393.2（12）A^3, Z = 4, F（000） = 1140, Dc = 1.540 g/cm^3, the final R = 0.0472 and wR = 0.0956 for 3204 observed reflections （I 〉2o（/））.

Syntheses and Crystal Structures of Two New Mercury(Ⅱ) Complexes with Double Betaine Ligands

Reaction of HgCl2 and double betaine ligands in water at about 80 ℃ yielded two new Hg（Ⅱ） complexes,[Hg（L1）Cl2]·H2O 1 and [Hg2（L2）Cl4]·3HgCl2 2（L1 = 1,3-bis（pyridinio-4-carboxylato）-propane,L2 = 1,4-bis（pyridinio-4-carboxylato）-1,4-dimenthylbenzene）.Their struc-tures have been characterized by single-crystal X-ray diffraction techniques.The structure of 1 contains 1-D chains,in which the adjacent Hg（Ⅱ） atoms are bridged by L1 ligands in a syn-syn bis-monodentate mode.The chains are further connected through face-to-face π-π stacking interactions between pyridine rings to generate an infinite double-chain network.In 2,two Hg（Ⅱ） atoms are joined by L2 ligands in the same coordination mode as 1 to form an isolated dinuclear structure.The thermal stabilities of both complexes have also been investigated.

Syntheses and Crystal Structure of Erbium(Ⅲ) Coordination Polymers with Two Flexible Double Betaine Ligands

Two new polymeric erbium(Ⅲ) complexes of two flexible double betaine ligands have been synthesized and characterized by X-ray analysis. In {[Er(L1)(H2O)4)Cl3 H2O}n (1) (L1 = 4, 4’ -trimethylenedipyridinio-N, N’-diacetate ), the erbium(Ⅲ) ions form a two-dimensional metal carboxylate layer in which each pair of Er(Ⅲ) atoms is bridged by two syn-anti μ-carboxylato-o,o’ groups, Adjacent layers arecross-linked through hydrogen bonds among aqua ligands, lattice water molecules andchloride ions to form a three-dimensional network. Complex l, C17 H28 N2 O9 ErC13 (Mr =676.0) is monoclinic, space group C2, with a= 27. 408(4), b= 9. 645 (3), c= 9. 423(2) A, p=1loo. 85(1)’, V=2446. 2(9) A’, Z=4, D=l. 836 g/cm’, F(OOO) =1332, μ(MoKa) = 38.06 cm-1, R=0. 048 for 2451 reflections with I>2σ(I). { [Er(L2 ) (H2O)4]Cl3. 5H2O}. (2) (L2=1, 3-bis (pyridinio-4-carboxylato) propane) comprises lanthanide carboxylate chains built from centrosymmetric dimeric units crosslinked by a pair of L2 ligands, discrete anions and lattice water molecules. In the dimeric unit of complex 2, each pair of metal ions is bridged by four syn-syn μ-carboxylatoO, O’ groups that are oriented nearly perpendicular to each other about the metal-metalaxis. The metal carboxylate chains of complex 2 are further cross-linked by hydrogenbonds to form a three-dimensional network. Complex 2, C15 H32 N2O13 ErCl3 (Mr=722.0) belongs to the monoclinic space group C2/m with a=16. 564 (3), b=15. 839(3), c=11. 792(4) , β=122. 27(1)°, V=2616(1), Z=4, Dc=1.833 g/cm3,F(000) =1436, μ (MoKa) = 35. 75 cm-1, R =0.043 for 2436 observed reflectionswithI>2σ(I).