The thesis is devoted to the synthesis and research of structures, physicochemical and functional properties of the new coordination compounds with multidentate N- and N,O-donor ligands. Based on comprehensive studies of the literature, two groups of organic compounds derivatives of o-vanillin and salicylic aldehyde (H2L1-H2L4) as well as little researched off shoots of 2,1,3-benzothiadiazole (HL5-L10) have been selected as promising polydentate ligands. The development of methods for preparation of a five new ligands HL5, HL6, L7, L9, L10 and forty-five coordination compounds have become the major outcome of the thesis. All new compounds were investigated by the modern physicochemical methods such as the IR-, NMR-, EPR-, UV, luminescent and atomic-emission spectroscopy as well as mass spectrometry and CHN-analysis. The crystal structures of 48 compounds (7 organic ligands and 41 coordination compounds), have been defined by X-ray crystallographic analysis. The results of the studies are supported by quantum mechanical calculations. The fields of the possible applications of prepared compounds and the potentials of further investigations have been suggested.
It has been shown that the composition and structure of the products containing H2L1-H2L4 are determined by the ratio of the starting materials, the nature of ammonium salts and the reaction conditions.
The accurate choice of the reaction conditions gave the possibility to obtain: а) series of d-s heterometallic Cu/М (M = Ca, Sr, Ba) complexes of two types – trinuclear with the general formula [M{Cu(HL1)2}2Xn(solv)m]X2- n(solv)l (n, m, l = 0-2; solv = CH3OH, H2O; X = Br, I, SCN, NO3) (3-9) and binuclear [Cu(L3)2Ca(NCS)2(H2O)] (12); b) tetranuclear complexes with Cu4O4 fragment cubic or pseudo-cubic structure [Cu4(L1)4(СH3OH)4]·2,2CH3OH (1) and [Cu4(HL1)2(L1)2(NCS)2(СH3OH)2]·2CH3OH (10); c) binuclear complex [Mn2(HL2)2(NCS)2]·2C2H5OH (19) with fragment {MnІІ(μ-O)2MnІІ}; d) polymeric manganese (III) complexes with the general formula MnІІІ(HL1,4)2Х (Х = Cl, Br, I, NCS) (13-18), which have cationic or neutral chains structure.
It was shown that the ligand H2L2 in the solid state exists in the different tautomeric forms defined by the nature of the solvent or the absence of the latter. Quantum chemical calculations of this ligand are in the good correlation with the results of X-ray structural data and reveal significant influence of hydrogen bonds on the stability of tautomeric forms. The ligand and its solvate forms show luminescent properties.
In the coordination polymers Mn(HL1,4)2X (Х = Cl, Br, I, NCS) (13-18) very weak antiferromagnetic exchange interactions between Mn(III) ions through {−NCCO−} bridges have been found; the obtained data were supported by EPR spectroscopy and quantum chemical calculations.
A new N,О-polydentate ligands (derivatives of 2,1,3-benzothiadiazole – HL5 and HL6) and their coordination compounds, namely, [М(L5,6)2]nCH2Cl2 (М = Cu, Co, Ni, Zn) (21-24, 26-28) have been prepared. N,О-bidentate and N,N,О-tridentate modes of the coordination have been revealed. On the example of [Cu(L5)(Hfac)] (25) the possibility of formation of multiligand complex was shown.
Three new N-polydentate ligands L7, L9 and L10 which are derivatives of 2,1,3-benzothiadiazole have been obtained by Suzuki coupling, their structure have been defined and quantum chemical calculations of their molecules have been done. The electrochemical properties of the these ligands were studied. The mono- and binuclear complexes with Mn, Co, Ni, Cu, Zn have been synthesized. The ligands L7 and L9 in the mononuclear complexes {М(L7,9)(Х)2(solv)n} (М = Mn, Co, Ni, Cu, Zn; X=Cl, Hfac; solv=H2O, C2H5OH, CH2Cl2) (28, 31-37, 40-43, 45-49) perform N,N-bidentate and N,N,N-tridentate-chelate functions. The {М2(μ-Cl)2} fragments containing the bridging chlorine atoms form binuclear complexes with general formula [М2(L7,9)Cl4(solv)n]·msolv (M = Ni, Co, Cu; solv = CH3OH, H2O) (29a-30, 44). The crystal structure of [CuL7Cl2] (30) consists of binuclear molecular complexes {Cu2(L7)2Cl4} and the neutral polymer chains {CuL7Cl2}n. The L8 ligand of multiligand complexes [CuL8(Hfac)2] (38) and [Cu2L8(Hfac)4] (39), has N,N-bidentate-chelate and N,N,N,N-tetradentate-chelate bridging functions.
It has been shown that the obtained compounds display luminescent properties and antimicrobial activity while polymer film composites based on polyvinyl butyral and heterometallic complexes reveal photoconductive, photovoltaic and photo-dielectric properties and can be used for the development of photovoltaic solar energy converters, recording media, antiseptics or disinfectants and luminescent materials.
