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

• Published in: Journal of molecular structure 2024-02, Vol.1297, p.136930, Article 136930
• Main Authors: Chen, Xinlei, Chen, Shiyi, Lin, Xuele, Zhou, Jingxuan, Gao, Xingjun, Zhen, Yaoqi, Ma, Xiaodan, Jin, Shouwen, Shi, Linfang, Liu, Hui, Wang, Daqi
• Format: Article
• Language: English
• Subjects: Carboxylic acids; Cd2; Coordination complexes; Hdmpz; Non-covalent linkages
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2023.136930

•Nine Cd2+ complexes of pyrazole-carboxylic acid have been prepared and characterized.•Non-covalent bonds have been ascertained.•Classical H-bonds are the primary forces.•Secondary interactions also have important role. Nine mixed-ligand Cd2+ complexes of [Cd(Hdmpz)2(bcaa)2] (1) (Hbcaa = 3-(benzylcarbamoyl)-acrylic acid), Cd4(Hdmpz)4(tcba)8(2) (Htcba = 2,4,6-trichlorobenzoic acid), [Cd(Hdmpz)(napa)2] (3) (Hnapa = 1-naphthoic acid), [Cd(Hdmpz)2(cnba2] (4) (Hcnba = 2-chloro-4-nitrobenzoic acid), Cd(Hdmpz)2(hmba)2 · H2O (5) (Hhmba = 4-hydroxy-3-methoxybenzoic acid), [Cd(Hdmpz)2(msal)2] (6) (Hmsal = 3-methylsalicylic acid), [Cd(Hdmpz)2(dbta)(H2O)] · 2H2O (7) (H2dbta = dibenzoyltartaric acid), [Cd(Hdmpz)4(tpda)] (8) (H2tpda = 2,5-thiophenedicarboxylic acid) and [Cd3(Hdmpz)6(btca)2(H2O)4] · 2H2O (9) (H3btca = 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···O H-bond from the N-H of the Hdmpz. 6 has the intramolecular O-H···O H-bond from the ortho phenol and the CO2−, resulting the S11(6) pattern. 5, 7 and 9 have the intermolecular O-H···O H-bond. 2, and 4-6 bear only the intermolecular N-H···O H-bond; 3, and 8-9 have only the intramolecular N-H···O H-bond. Compounds 1 and 7 bear both the intra- and intermolecular N-H···O H-bonds. There featured intricate intra- and intermolecular classical H-bonds (N-H···O/O-H···O) together with CH-π/CH2-π/CH3-π, CH3-CH/CH3-CH3, CH3-C, CH-O/CH3-O, CH-Cl/CH3-Cl, Cl-O, Cl-π, O-π, 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. For the cooperative effect of the extensive weak non-covalent interactions, the complexes displayed 2D-3D structures. [Display omitted]