Nine Cd2+ complexes containing 3,5-dimethylpyrazole and carboxylic acids: Synthesis, spectroscopic and crystallographic characterization

Nine mixed-ligand Cd2+ complexes of [Cd(Hdmpz)(2)(bcaa)(2)] (1) (Hbcaa = 3-(benzylcarbamoyl)-acrylic acid), Cd-4(Hdmpz)(4)(tcba)(8) (2) (Htcba = 2,4,6-trichlorobenzoic acid), [Cd(Hdmpz)(napa)(2)] (3) (Hnapa = 1-naphthoic acid), [Cd(Hdmpz)(2)(cnba(2)] (4) (Hcnba = 2-chloro-4-nitrobenzoic acid), Cd(Hdmpz)(2)(hmba)(2) center dot H2O (5) (Hhmba = 4-hydroxy-3-methoxybenzoic acid), [Cd(Hdmpz)(2)(msal)(2)] (6) (Hmsal = 3-methylsalicylic acid), [Cd (Hdmpz)(2)(dbta)(H2O)] center dot 2H(2)O (7) (H(2)dbta = dibenzoyltartaric acid), [Cd(Hdmpz)(4)(tpda)] (8) (H(2)tpda = 2,5-thiophenedicarboxylic acid) and [Cd-3(Hdmpz)(6)(btca)(2)(H2O)(4)] center dot 2H(2)O (9) (H(3)btca = 1,2,4-benzenetricarboxylic acid) were synthesized and formulated by EA, IR spectra + SCXRD, their TGA were also conducted. The SCXRD reports indicated that the complexes exhibit mononuclear to tetranuclear structures with octahedral geometry at the Cd2+. The Hdmpzs in all examples are coordinated only through the monodentate fashion with its neutral N. The carboxylate at 8 displays only as unidentate coordination, while the ones in 1, 4 and 5-7 take the chelating bidentate coordination mode. The CO2- at 2-3 adopts both the chelating bridging tridentate and bismonodentate coordination fashion. 9 contains both unidentate and bidentate chelating coordinate CO2-. There all existed the N-H center dot center dot center dot O H-bond from the N-H of the Hdmpz. 6 has the intramolecular O-H center dot center dot center dot O H-bond from the ortho phenol and the CO2-, resulting the S-1(1)(6) pattern. 5, 7 and 9 have the intermolecular O-H center dot center dot center dot O H-bond. 2, and 4-6 bear only the intermolecular N-H center dot center dot center dot O H-bond; 3, and 8-9 have only the intramolecular N-H center dot center dot center dot O H-bond. Compounds 1 and 7 bear both the intra- and intermolecular N-H center dot center dot center dot O H-bonds. There featured intricate intra- and intermolecular classical H-bonds (N-H center dot center dot center dot O/O-H center dot center dot center dot O) together with CH-pi/CH2-pi/CH3-pi, CH3-CH/CH3-CH3, CH3-C, CH-O/CH3-O, CH-Cl/CH3-Cl, Cl-O, Cl-pi, O-pi, O-C plus O-O associates which are illuminated by the X-ray crystallographic technique, tethering the discrete units into high-dimensional ordered supramolecular systems.

Automated summary

Nine mixed-ligand Cd2+ complexes with different geometric structures were synthesized and characterized. The complexes exhibit various coordination modes and form both intra- and intermolecular hydrogen bonds.