As part of our systematic research on the acentric rare earth chalcogenides, the ErAlGeS5/KBr, Er3AgGeS7/KBr and Er6Ge3S14/KBr systems were investigated and three compounds belonging to the R6B2C2Q14 （R = rare earth, B = 6-coordinated element, C = 4-coordinated element, Q = S and Se） family were identified. These compounds crystallize in the P63 space group, and the crystal data are as follows： Er3Ge1/4GeS7, a = 9.6480（14）, c = 5.7920（12） A^°, Z = 2; Er3Ge0.382（8）GeS7, a = 9.6360（14）, c = 5.8460（12） A^°, Z = 2; Er3Ge1/2GeS7, a = 9.6061（13）, c = 5.8346（18）A^°, Z = 2. Single-crystal analysis indicated that the Er3GexGeS7 （x = 1/4, 0.382（8）, 1/2） structures consist of three types of building blocks： ErS7, GeS4 and GeS6 units. Er3MxGeS7 are deficient compounds with the B sites occupied partly by Ge（Ⅳ） and/or Ge（Ⅱ）.
A new cadmium（Ⅱ） coordination polymer,namely,[KCd2（edta）I]n（1,H4edta = ethylenediaminetetraacetic acid）,has been prepared and structurally characterized by single-crystal X-ray diffraction.Crystallographic data for 1：C10H12Cd2IKN2O8,Mr = 679.02,monoclinic,space group P21/n,a = 9.870（5）,b = 8.989（4）,c = 19.082（10） ,β = 104.581（10）o,V = 1638.5（13） 3,Z = 4,Dc = 2.753 g/cm3,μ = 4.776 mm-1,F（000） = 1272,the final R = 0.0473 and wR = 0.1311 for 2846 observed reflections with I 〉 2σ（I）.Polymer 1 features a 2-D layered structure,in which each edta4-ligand chelates/bridges five adjacent six-/seven-coordinated Cd（Ⅱ） centers with all ten donors（eight oxygen and two nitrogen） involved with coordination.Additional iodide I-ions as counterions are bound to the Cd（Ⅱ） centers in a terminal mode and the potassium K＋ ions are located in the layers and surrounded by O and I atoms from neighboring environment.The thermal stability of 1 has been discussed.
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.
The solution reactions of the metal salts with 2,2＇-bipyfidine （2,2＇-bipy） and ethyl tetrazole-5-carboxylate （Hetzc） afforded two new tetrazole-based complexes M（2,2＇-bipy）2（etzc）2 （M=Mn 1, Zn 2）, and their crystal structures were determined by single-crystal X-ray diffraction analyses. Crystallographic data for 1： C28H26MnN12O4, Mr = 649.55, monoclinic, space group C2/c, a= 19.326（15）, b = 11.051（6）, c = 16.388（13）А,β= 117.38（4）° V= 3108（4） А^3, Z= 4, Dc = 1.388 g/cm^3, F（000） = 1340, R = 0.0557 and wR = 0.1269; and those for 2： C28H26ZnN12O4, Mr = 659.98, monoclinic, space group C2/c, a = 19.173（4）, b = 11.006（2）, c = 16.266（4） А, β= 118.11（3）°, V= 3027.4（11） А^3, Z = 4, Dc=1.448 g/cm3, F（000） = 1360, R = 0.0428 and wR = 0.1000. The structures of 1 and 2 are isomorphic and consist of isolated neutral mononuclear units. The metal atoms have highly distorted octahedral coordination environments with two N atoms from two etzc ligands and four N atoms from two 2,2＇-bipy molecules. The isolated mononuclear units are connected by π…π stacking interactions to generate one-dimensional chains. The thermal stability and photoluminescence have also been discussed.
