Construction of several d10 metal coordination polymers based on aromatic polycarboxylate and flexible triazole-based ligand

Structural and DFT Studies on the Polymorphism of a Cadmium(II) Dipicolinate Coordination Polymer

“…The bond angles around cadmium­(II) ions indicate a distortion from the ideal pentagonal-bipyramidal geometry which is also reflected in the bite angles N1–Cd1–O3, N1–Cd1–O5, N2–Cd2–O8, and N2–Cd2–O10 for 1 with values in the range 67.0(1)–69.1(1)° and in the bite angles N1–Cd1–O3, N1–Cd1–O5, N2–Cd2–O9, and N2–Cd2–O11 for 2 with values in the range 66.53(8)–69.19(8)° (Table S1 in the Supporting Information). The Cd–N and Cd–O bond distances in these polymorphs (Table ) are comparable with the corresponding ones reported in the literature for related mononuclear, − binuclear, , and polynuclear cadmium­(II) complexes with dipicolinic acid − or with its ethyl ester or with 4-hydroxydipicolinic acid. , …”

“…15−30 According to the Cambridge Structural Database (CSD), 31 there are four structurally characterized cadmium(II) coordination polymers with dipicolinate and additional ligands, e.g. methanol, 15 1,4-bis(imidazol-1-ylmethyl)benzene, 16 (1,2,4-triazol-1-ylmethyl)-benzene, 17 or cocrystallized complexes, e.g. a copper picolinate complex, 18 which has been reported in the literature.…”

“…Therefore, it often appears as an organic linker in coordination chemistry. It can interact with metal ions in both its fully deprotonated (dipic) and partially deprotonated forms (dipicH) and is widely used for the preparation of the various metal complexes, as evidenced by the number of coordination compounds of this ligand with cadmium alone. − …”

Unsaturated Iridium(III) Complexes Supported by a Quinolato–Carboxylato ONO Pincer-Type Ligand: Synthesis, Reactivity, and Catalytic C–H Functionalization

“…Some support for this hypothesis comes from a study of the IR spectra (ATR) of the complexes, which show strong vibrations around 1675–1550 and 1450 cm –1 corresponding to the asymmetric and symmetric stretching modes of the carboxylate group, respectively . In particular, the asymmetric stretching mode of higher energy, in the 1675–1637 cm –1 range for the complexes reported herein, was observed at an unusually low frequency of 1615 cm –1 in the ATR spectrum of 3 . In contrast, this absorption was observed at 1683 cm –1 in THF solution.…”

Syntheses, Crystal Structure, and Fluorescent Property of a New Cd(II) Complex Constructed from 1,2,4,5-Benzenetetracarboxylate

“…A large number of complexes with aromatic polycarboxylic acids have been reported, such as the complexes based on 1,2-benzenedicarboxylic acid (o-H 2 bdc), 1,3-benzenedicarboxylic acid (m-H 2 bdc), 1,4-benzenedicarboxylic acid (p-H 2 bdc), [4][5][6] 1,3,5-benzenetricarboxylic acid (H 3 btc), [7][8][9][10] 1,2,4-benzenetricarboxylic acid (H 3 btc), [11] and 1,2,4,5-benzenetetracarboxylate acid (H 4 btec). [12][13][14][15][16][17] Among these aromatic polycarboxylic acids, 1,2,4,5-benzenetetracarboxylate acid (H 4 btec) possesses several interesting characteristics: (a) it has four carboxyl groups which may be partially or completely deprotonated, and can coordinate to the metal ions in a wide variety of coordination modes, allowing interesting structures with higher dimensions; (b) it can act not only as hydrogenbond acceptor but also as hydrogen-bond donor, depending on the numbers of deprotonated carboxyl groups; and (c) some of the carboxyl groups may not lie in the phenyl ring plane upon complexation to metal ions owing to steric hindrance, thus, it can connect metal ions in different directions. [1,18] Herein, we selected H 4 btec (1,2,4,5-benzenetetracarboxylic acid), which exhibits high symmetry, diverse charge and multiconnecting ability as ligand, to react with Cd(NO 3 ) 2 ·4H 2 O under hydrothermal condition (120 • C) and a new 1-D chain structure complex {[Cd(btec) 0.5 (H 2 O) 3 ]·H 2 O} n (1) has been obtained and characterized by elemental analysis, IR, single crystal X-ray diffraction analysis and fluorescence spectroscopy.…”