The novel developed synthesis methods allowed to obtain three Ge(IV)-Co(II) coordination compounds with 1- hydroxyethylidenediphosphonic acid and 2,2`-bipyridine [{Co(bipy)3}2{Co(bipy)(H2O)4}2][{Ge(μ-OH)(μ-hedp)}6Cl2]∙2H2O (1), [Co(bipy)3]4[{Ge(μ-OH)(μ-hedp)}6Cl2]∙30H2O (2), [Co(bipy)3]3[{Ge(μ-OH)(μ-hedp)}6]⋅20Н2О⋅2CH3COOH (3). Complexes are characterized by the methods of elemental analysis, IR-, Diffuse Reflectance spectroscopy, thermogravimetric analysis. All absorption bands presented in the IR-spectra of compounds 1-3 are highlighted in the Table 2. Absorption bands of the P-O bond are detected at ~1053 and ~970 сm-1, that indicates the presence of the fully deprotonated PO32- groups in the composition of complexes. Furthermore, n(OH), ν(Ge–Ophosph), d(Ge–OH) bands characteristic for all the previously synthesized compounds with [Ge6(m-OH)6(m-hedp)6]6-anion is detected in the IR spectra of 1-3. Presence of the crystal water molecules is confirmed by the ν(OH) at 3400 сm-1. A set of the bands usual for the aromatic molecules (n(C–Harom), n(C–Carom), das(CH3), ds(CH3), n(С–N)) is assigned with 2,2`-bipyridine in the structure of all compounds. A special feature of the IR-spectra of 1 is presence of COOH absorption band at 1700 сm-1, that indicates the location of solvated acetic acid. Complex 1 also contains coordination water molecules, confirmed by the d(H2O) at 1642 сm-1 in its IR-spectrum. Absorption bands of Co–N and Со-О bonds evidence that 2,2`-bipyridine and H2O molecules are coordinated to the cobalt atom. Thermal decomposition of 1-3 differs a lot. Variable interval and temperature of the first endoeffect is explained by the different nature of water in them – crystal (1-3) and coordinated (1). In the diffuse reflection spectra of compounds 1-3, two bands corresponding to the following transitions are observed: 4T1g(F)→ 4T2g (1 – 7250, 2 – 7100, 3 – 7300 сm-1), 4T1g(F)→ 4T1g(P) (1 – 13800, 2 – 14200, 3 – 14000 сm-1). Such results confirm an octahedral configuration of cobalt atom. There was also established, how composition and structure of the synthesized compounds depend from the molar ratio of the reagents and anion of the initial Co(II) salt (chloride, acetate).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.