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In the present study, through employing the mixed ligands of tetrakis(4-carboxyphenyl)silane (H4TCS) and 1,4-bis(2-methylimidazol-1-yl)benzene (BMIB), we have triumphantly created two coordination polymers (CPs) [Co2(TCS)(BMIB)2](DMF)3(H2O)2 (1) and [Co2(H2TCS)2(BMIB)2] (2) with the reaction between the H4TCS ligand and BMIB ligand and Co(NO3)2·6H2O in distinct systems of solvent. Their application values on the acute myocardial infarction were assessed, and then their corresponding mechanism was investigated. Firstly, the ELISA detection assay was performed for the detection of the inflammatory cytokines levels released into plasma during acute myocardial infarction. In addition to this, the real-time RT-PCR was performed and the lncRNA-CAIF levels were determined.

Through precisely adjusting the pH value of reaction system, two new mixed-ligand based coordination polymers, namely [Zn(ip)0.5(bta)]n (1) and [Zn3(Hip)4(bta)2]n (2) (H2ip = isophthalic acid, Hbta = benzotriazole), have been acquired through the self-assemble reaction of Zn(II) salts in combination with H2ip and Hbta. Both compounds have high thermal stability demonstrated by the thermogravimetric analysis (TGA) experiments, and exhibit strong luminescence emission at room temperature. Their application values on the children bone growth and development were evaluated and the specific mechanism was examined simultaneously. Above all, compound 1 was more outstanding than compound 2 against the children bone growth and development by regulating the Vitamin K receptor on the bone cell surface.

In the current study, by using the mixed ligand approach, a novel 2D metal–organic framework (MOF), [Zn(Hssa)(1,4-dtb)·H2O]n (H3ssa = 5-sulfosalicylic acid, dtb = 1,4-di(4H-1,2,4-triazol-4-yl)benzene) was synthesized with a high yield under solvothermal reaction conditions and through the elemental analysis and the single-crystal X-ray diffraction. Luminescence studies demonstrate that 1 is able to be utilized as a strongly sensitive luminescent sensor for Cr2O72− and CrO42− in H2O. Furthermore, the neuroprotective effect of the compound on CO poisoning patients was evaluated in biological research. The real-time RT-PCR was conducted to study the expression level of the ROS-related genes in the neurons. In addition to this, the activation of the superoxide dismutase (SOD) in the neurons was measured after treatment of the compound.

Mixed ligand complexes of copper(II) and nickel(II) with glycine (Gly) and histidine (His) have been studied in aqueous solution using calorimetric, potentiometric and spectrophotometric data at 298.15 K and the ionic strength of I = 0.5 mol·L–1 (KNO3). The thermodynamic parameters of formation of various mixed complexes have been determined. The probable coordination modes of amino acid residues in mixed ligand complexes is discussed.

The interaction of triethanolamine (TEA) with Cu(II) salts of salicylic, cinnamic and succinic acids was studied for the first time. The structure of the synthesized complexes was investigated by single-crystal X-ray diffraction. TEA complexes with Cu(II) salicylate (1) and cinnamate (2) are binuclear mixed ligand complexes, but interaction of TEA with Cu(II) succinate leads to the formation of cationic mononuclear complex—[Cu(TEA)2](C4H4O4) (3). Cu(II) complexes 1–3 were also characterized by physicochemical and spectroscopic methods. Their antimicrobial activity was investigated.

Two 3D mixed-ligand coordination compounds, [Cd(1,3-bdc)(bmip)]n [1, H21,3-bdc = 1,3-benzenedicarboxylic acid, bmip = 1,3-bis(2-methyl-1H-imidazol-1-yl)propane] and [Cd(5-mpc)(bmip)]n (2, H25-mpc = 5-methylisophthalic acid), have been successfully synthesized under hydrothermal conditions and characterized successfully by single crystal X-ray analysis. In addition, in vitro anticancer activities of compounds 1 and 2 on three human liver cancer cells (PLC/PRF/5, BEL-7404 and MHCC97-L) were further determined.

The stability constant and coordination modes of the multimetal–multiligand complexes of M2+ ions (M = M1 = M2 = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with nitrilotriacetic acid (A) and l-2-amino-3 methyl butanoic acid (B) were studied potentiometrically by Calvin-Bjerrum’s method in the biologically relevant condition. The experimental data were obtained for the following model species, AH3, AH2, AH, BH2, BH, M(OH)+, M(OH)2, MA, MA(OH), MB, MAB and M1M2AB. The observed order of stability constant and percent distribution of different complex species with respect to pH was discussed. The calculation was made using the SCOGS computer program. The ternary species [AMB]2− and quaternary species [M1M2AB] were found to be in the range of pH 7–10 and 3–8 pH, respectively.

The Vilsmeier–Haack formylation reactions with hydrocarbons are sluggish in acetonitrile medium. The VH reactions follows second-order kinetics and affords formyl derivatives under kinetic conditions that are also irrespective of the nature of the oxychloride (POCl3 or SOCl2) used for the preparation of VH reagent along with DMF. However, the reactions undergo significant rate accelerations in the presence of transition metal ions such as Cu(II), Ni(II), Co(II) and Cd(II). Transition metal ion catalyzed VH formylation is explained through the formation of a mixed ligand complex of the [M(II)S(VHR)] type prior to the rate determining rearrangement step, before yielding formyl derivatives of hydrocarbons.

When studying the synthesis of NBu4[Co(piv)3] and NBu4[Cu(piv)3], where NBu4 is a tetrabutylammonium cation and piv is a pivalate anion, in some cases we obtained a few crystals of the tetranuclear complexes (NBu4)2[M4(piv)8(AcO)2(H2O)n], where M = Co, n = 4; M = Cu, n = 2, AcO is the acetate anion. These complexes contain only deprotonated pivalate and acetate anions as coordinated organic ligands and represent a rare type of polynuclear compounds, which have not been obtained earlier as the major individual phase. For CoII, a method was developed for the straightforward synthesis of the complex (NBu4)2[Co4(piv)8(AcO)2(H2O)4].

The series of adducts of magnesium beta-diketonates with diamimes namely Mg(thd)2(tmeda) 1 and four new complexes Mg(thd)2(tmpda) 2, Mg(thd)2(pda) 3, Mg(ptac)2(tmeda) 4, Mg(tfac)2(tmeda) 5 [beta-diketonates = R1C(O)CHC(O)R2: thd (R1 = R2 = t Bu), ptac (R1 = t Bu, R2 = CF3), tfac (R1 = Me, R2 = CF3); diamines = R2N(CH2) n NR2: tmeda (n = 2, R = Me), tmpda (n = 3, R = Me), pda (n = 3, R = H)] were synthesized in order to investigate the influence of both ligand types on the thermochemical properties of these compounds. The thermal behavior of the complexes in the condensed phase was investigated by thermogravimetry and differential scanning calorimetry; the thermodynamic parameters of phase transitions were determined. The saturated vapor pressure of solid complexes Mg(thd)2(tmeda) and Mg(tfac)2(tmeda) were measured by the transmission method giving the enthalpies and entropies of sublimation processes. The reliable thermodynamic data for compound Mg(thd)2(tmeda) were obtained with the assistance of X-ray diffraction and the static method of saturated and unsaturated vapor pressure measurements.

The synthesis and photoluminescence spectra of mixed-ligand complexes of Nd(III), Yb(III), and Er(III) with dibenzoylmethanate anion as the principal ligand and functionalized 1,2,4-triazoles and spacer bis-triazoles as ancillary ligands were described.

The mixed-ligand complex formation in the systems Cu2+–Edta4−–L (L = His, Lys, Orn, Arg, Im) has been calorimetrically, pH-potentiometrically, and spectrophotometrically studied in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO3). The thermodynamic parameters of formation of the CuEdtaL, CuEdtaHL, and (CuEdta)2L complexes have been determined. The probable coordination mode for the complexone and the ancillary ligand in the mixed-ligand complexes was discussed.

Spectral and luminescent properties of mixed-ligand Eu(III) complexes were studied in solutions and in polyvinylcarbazole (PVC) thin films. Trends in their variations were found depending on the complex structure and excitation mode. The electroluminescence was observed in ITO/PEDOT/Eu complex:PVC/CaMg/Al devices. Their current-voltage and voltage-brightness characteristics were investigated.

The mixed-ligand complex formation in the system Cu2+−Edta4−−(CH2)6(NH2)2 (L), where L is hexamethylenediamine has been calorimetrically, pH-potentiometrically and spectrophotometrically studied in aqueous solution at 298.15 K and the ionic strength of I = 0.5 (KNO3). The thermodynamic parameters of formation of the CuEdtaL2−, CuEdtaHL− (CuEdta)2L4− and (CuEdta)2En4− complexes have been determined. The most probable coordination mode for the complexone and the ancillary ligand in the mixed-ligand complexes was discussed.

Mixed-ligand NiII complexes have been synthesized with 1,3-diketonate and bulky tri- or tetra-amine ligands. Their structures were determined by X-ray crystallography, and solvatochromic behavior was examined by UV–vis–NIR spectroscopy. Steric effects of the bulky ligands on the coordination distances and spectral properties are discussed.

The reaction of NiCl2 with excess potassium pivalate (KPiv) in ethanol affords the chainpolymeric compound KNi4(Piv)7(OH)2(EtOH)6. In the solid compound, the tetranuclear nickel fragments alternate with potassium atoms. The use of KNi4(Piv)7(OH)2(EtOH)6 in the reaction with Ni(hfac)2 (hfac is the hexafluoroacetylacetonate anion) gave the first polynuclear mixed-ligand complexes [K2Ni6(Piv)7(hfac)3(OH)4(HPiv)2(Me2CO)2]·1.5C7H16, [Ni6(Piv)4(hfac)4(OH)4(Me2CO)4], [K2Ni8(Piv)8(hfac)4(OH)6(H2O)2(Me2CO)6], [Ni8(Piv)10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2]·C6H14, and [Ni16(Piv)10(hfac)6(OH)10(MeO)6(MeOH)8(H2O)6]·C6H14 containing both Piv and hfac as the anionic ligands. The molecular and crystal structures of all these compounds were established, and their magnetic properties were studied. All solids containing simultaneously Piv and hfac ligands tend to undergo ferromagnetic ordering with decreasing temperature. The solid [Ni8(Piv)10(hfac)2(OH)2(MeO)2(MeOH)2(HPiv)2]·C6H14 undergoes cooperative magnetic ordering below T c (2.5 K).

A method was developed for the synthesis of mixed-metal heterospin compounds with the direct coordination of the nitroxide fragment based on the replacement of acetonitrile molecules in the heterotrinuclear complex [Co2Gd(NO3)Piv6(CH3CN)2] with nitroxide molecules. The molecular and crystal structure of the heterospin mixed-ligand heterotrinuclear CoII, GdIII, CoII complex [Co2Gd(NO3)Piv6(NIT-Me)2], where NIT-Me is stable nitronyl nitroxide, was established. The magnetic properties of this complex were investigated in the temperature range of 2–300 K. The coordination of nitroxide groups to CoII ions is responsible for strong exchange interactions between the unpaired electrons in the exchange clusters {>-·O-CoII}, resulting in the virtually complete spin coupling between each coordinated >N-·O group and one of the unpaired electrons of each CoII ion at temperatures below 200 K.

Interesting varieties of heterobimetallic mixed-ligand complexes [Zr{M(OPri) n }2 (L)] (where M = Al, n = 4, L = OC6H4CH = NCH2CH2O (1); M = Nb, n = 6, L = OC6H4CH = NCH2CH2O (2); M = Al, n = 4, L = OC10H6CH = NCH2CH2O (3); M = Nb, n = 6, L = OC10H6CH = NCH2CH2O (4)), [Zr{Al(OPri)4}2Cl(OAr)] (where Ar = C6H3Me2-2,5 (5); Ar = C6H2Me-4-Bu2-2,6 (6), [Zr{Al(OPri)4}2(OAr)2] (where Ar = C6H3Me2-2,5 (7); Ar = C6H2Me-4-Bu2-2,6 (8), [Zr{Al(OPri)4}3(OAr)] (where Ar = C6H3Me2-2,5 (9); Ar = C6H3Me2-2,6 (10), [ZrAl(OPri)7-n (ON=CMe2) n ] (where n = 4 (11); n = 7 (12), [ZrAl2(OPri)10-n (ON=CMe2) n ] (where n = 4 (13); n = 6 (14); n = 10 (15) and [Zr{Al(OPri)4}2{ON=CMe(R)} n Cl2–n] [where n = 1, R = Me (16); n = 2, R = Me (17); n = 1, R = Et (18); n = 2, R = Et (19)] have been prepared either by the salt elimination method or by alkoxide-ligand exchange. All of these heterobimetallic complexes have been characterized by elemental analyses, molecular weight measurements, and spectroscopic (I.r., 1H-, and 27Al- n.m.r.) studies.

Equilibrium study on the mixed ligand complex formation of CuII with biguanide(Bg) and glycine (HG), indicated the formation of the complexes: Cu(Bg)2+, Cu(Bg) 2 2+ , Cu(Bg-H)(Bg)+, Cu(Bg-H)2, Cu(Bg)(OH)+, Cu(Bg-H)(OH); Cu(G)+, Cu(G)(OH), Cu(G)2; Cu(G)(Bg)+, Cu(G)(Bg-H); (G)Cu(Bg)Cu(G)2+, (G)Cu(Bg-H)Cu(G)+, and (G)Cu(Bg-2H)Cu(G). From the deprotonation constants of coordinated biguanide (Bg) in the complexes Cu(Bg)(OH)+, Cu(Bg-H)(Bg)+ and Cu(G)(Bg)+, the Lewis basicities of the coordinated ligand species (Bg-H)-, OH- and glycinate (G-) were found to be of the order: (Bg-H)-≫ OH- > G-. Bridging (N1-N4, N2-N5) tetradentate mode of coordination by biguanide species Bg, (Bg-H)- and (Bg2H)2- was indicated from the occurrence of biguanide-bridged dinuclear mixed ligand complexes (G)Cu(Bg)Cu(G)2+, (G)Cu(Bg-H)Cu(G)+, (G)Cu(Bg-2H)Cu(G) in the complexation equilibria.

Mixed ligand complexes of gold(I) with various selenones and Me3P, [Me3PAuSe=C C=Se mode of selenones upon complexation is indicative of selenone binding to gold(I) via a selenone group. An upfield shift in 13C-n.m.r. for the >C=Se resonance of selenones and downfield shifts in 31P-n.m.r. for Me3P moiety are consistent with the selenium coordination to gold(I). The steric effect as well as the basicity of Me3PAu+ plays a significant role in bonding with Se-containing ligands compared to the Et3PAu+ and Ph3PAu+ complexes.

Parent and mixed-ligand cobalt(II) complexes of different compositions were prepared with water, sulfate ion and 1,2-ethanediol as ligands. The magnetic susceptibility data, the IR spectra and the thermoanalytical curves of the complexes were recorded. Oxygen atoms bound by one or two coordinate bonds to the metal ion, or by hydrogen-bonds were observed in the crystals pace.

Two new mixed ligand ruthenium(I) complexes of the composition [Ru2(O2CR)2(CO)5] (where R = (2,4-CF3)2C6H3 (1) and (3,5-CF3)2C6H3 (2)) have been prepared by melt reactions, and both have been fully characterized. Crystals of 1 and 2 have been obtained by gas phase sublimation of crude products at 124 and 150°C, respectively. The X-ray diffraction studies have revealed a tetranuclear ‘dimer of dimers’ core structure in both cases. In 1 two diruthenium(I) units cis-bridged by two carboxylates each are coordinated through the Ru···FO axial interactions at 2.301(2) A. In contrast, complex 2 shows the direct Ru···FRu bonding of two diruthenium units at 2.9065(9) A. The Ru–Ru distances within the dinuclear units are 2.6654(7) and 2.6859(8) A in 1 and 2, respectively.

A reaction of complexes CoCl2(dppe) (dppe is the 1,2-bis(diphenylphosphino)ethane) or CoCl2(dppp) (dppp is the 1,3-bis(diphenylphosphino)propane) with [K][7,8-nido-C2B9H12] upon reflux in benzene led to the mixed ligand closo-cobaltacarboranes [3,3-(Ph2P(CH2) n PPh2)-3-Cl-closo-3,1,2-CoIIIC2B9H11] (n = 2 and 3, respectively) in moderate yields (34 and 16%). The structure of the 18-electron complexes in solution and the solid state was studied by NMR and IR spectroscopy, the structure in the case of the closo-complex with dppe-ligand was confirmed by X-ray crystallography.

A number of mixed ligand complexes of gold(I) with various selenones and Ph3P, [Ph3PAuSe=C

In order to obtain the standard molar enthalpies of formation of Rare-Earth amino acid coordination compounds, precise isothermal solution-reaction calorimetric method was used. The value of ΔrH m Θ of two coordination reactions was determined at T=298.2 K. From the experimental results and other auxiliary values, the standard molar enthalpies of formation of Ln(Gly)5/2(Ala)3/2(ClO4)3·H2O(s) [Ln=La, Yb] at T=298.2 K were obtained. The values of them is to be ΔrH m Θ [La(Gly)5/2(Ala)3/2(ClO4)3·H2O(s)]=−3545.45 kJ/mol and ΔrH m Θ [Yb(Gly)5/2(Ala)3/2)(ClO4)3·H2O(s)]=−3793.81 kJ/mol, respectively.

Two lactates and four new mixed ligand complexes with formulae Co(lact)2·2H2O, Ni(lact)2·3H2O, Co(4-bpy)(lact)2, Co(2,4'-bpy)2(lact)2, Ni(4-bpy)(lact)2·2H2O and Ni(2,4'-bpy)2(lact)2 (where 4-bpy=4,4'-bipyridine, 2,4'-bpy=2,4'-bipyridine, lact=CH3CH(OH)COO-) were isolated and investigated. The thermal behaviour of compounds was studied by thermal analysis (TG, DTG, DTA). In the case of hydrated complexes thermal decomposition starts with the release of water molecules. The compounds decompose at high temperature to metal(II) oxides in air. A coupled TG-MS system was used to analyse the principal volatile products of thermolysis and fragmentation processes of obtained complexes.

The interaction of Zn(II), Cd(II), and Pb(II) with 1,10-phenanthroline noncovalently immobilized on silica in the presence of Bromophenol Blue was studied. The optimum conditions of the reaction and the composition of mixed-ligand complexes that are formed at the surface were found, and a scheme was proposed for the interaction at the interface. A sorption–spectrophotometric procedure and a test scale were developed for the determination of zinc with detection limits of 0.011 and 0.018 mg/L, respectively. The procedure was used for the determination of labile zinc species in soil.

The research in the last decade has been mainly aimed at the development of technetium-99m radiopharmaceuticals, among which are the “3+1”mixed ligand complexes. Two novel [99mTc]“3+1”mixed ligand complexes each carrying the tridentate ligand, the N-(o-Methylthiophenyl)ethylenediamine or the N-(o-Methylthiophenyl)-b-mercaptoacetamide in combination with monothiolate coligand were produced using stannous chloride as reductant and glucoheptonate as transfer ligand. The identification of [99mTc]-6 and [99mTc]-7 was established by thin layer chromatography. The radiochemical purity of two complexes was over 90%. Biodistribution data in mice showed that both [99mTc]-6 and [99mTc]-7 can penetrate the intact blood-brain barrier and exhibited retention in mice brain. The brain uptakes (%ID/g) were 1.76, 1.17, 0.90 and 0.68, 0.38 ,0.37 at 2, 30, and 60 minutes i.v. postinjection for [99mTc]-6 and [99mTc]-7, respectively. Examples in this report comfirm us that it is promising to develop 99mTc complexes as potential brain perfusion agents based on modifying either the tridentate or the monodentate ligands.

Formation of the mixed-ligand complex [MnEdtaNH3]2– and of the Mn(II) ammine complex is studied by calorimetry at 298.15 K and ionic strength I = 0.5 (NH4NO3). Thermodynamic parameters of the reaction of attachment of the additional ligand to the manganese(II) chelate are determined; its probable mechanism is discussed.

A series of mixed ligand AuI complexes with selenourea (Seu) and various phosphines, [R3PAuSeu]Cl, have been prepared and characterized by elemental analysis, i.r. and n.m.r. methods. A decrease in the i.r. frequency of the C=Se mode of Seu upon complexation is indicative of AuI binding via a selenone group. An upfield shift in the 13C-n.m.r. for the C=Se resonance of Seu, and downfield shifts in 31P-n.m.r., for the R3P moiety are consistent with selenium coordination to AuI.

A series of Ru(N–N)2(dcbp or mcmabp) complexes were synthesized where N-N represents a diimine ligand, dcbp is 4,4′-dicaboxylic 2,2-bipyridine, and mcmabp is 4,4′-2,2′-bipyridine monocarboxy amide. The N-N ligand was either 2,2′-bipyridine (bpy), 4,4′-dimethyl-2,2′-bipyridine (dmbp), or 4,4′,5,5′-tetramethyl-2,2′-bipyridine (tmbp). We observed a red shift in both the absorption and emission with the presence of dcbp in the mixed ligand complex when compared to Ru(bpy)3. Conversion of one of the carboxylic groups in dcbp to amide resulted in further red shifts. A red shift in the absorption and the emission was also observed with increasing numbers of electrons donating methyl substitutions on bpy. The lifetimes of the complexes decreased as expected with the red shift emission. The tris heteroleptic Ru (tmphen)(tmbp)(dcbp or mcmabp) were the most red-shifted among the complexes. Because of the red shift in the absorption, the maxima in the fundamental anisotropies of the mixed ligand Ru complexes are now coincident with the maxima in the absorption. Overall we have been able to make an Ru complex which emits at about 700 nm in all aqueous environment and has a lifetime of about 220 ns.

Comparative analysis of the donor-acceptor capacities of diphosphine ligands in two series of complexes: cis-[Ru(bpy)2(LL)]q+ [LL = 2,2'-bipyridine (bpy), o-benzoquinonediimine (bqdi), cis-1,2-bis(diphenylphosphino)ethane, cis-1,2-bis(diphenylphosphino)ethylene (dppen), (NH3)2, and (CO)2] and [Ru(NH3)4. (LL)]2+ (LL = bpy, dppen, and bqdi), was performed. Diphosphines are the strongest σ donors; they compare in π-acceptor capacity which is associated with phosphorus d orbitals with 2,2'-bipyridine and fall far short of o-benzoquinonediimine and carbonyl.

Europium complexes with toluic acid having the composition Eu(Tol)3· nD · xH2O, where Tol–is the meta-toluate anion, D is 1,10-phenanthroline (n= 2, x= 1), 2,2"-dipyridyl, piperidine, diphenylguanidine, triphenylphosphine oxide (n= 1, x= 2), and H2O (n= 0, x= 2), were synthesized. The spectroscopic and luminescence properties of these complexes were studied. The title compounds are thermally stable up to 270°C. According to IR spectroscopy, two modes of coordination of the toluate anion, i.e., monodentate and bidentate coordination, can be found in europium toluates.

Volatile mixed-ligand compounds of Cd(i-Bu2PS2)2with Phen, 2,2"-Bipy, and 4,4"-Bipy were synthesized. Their single crystals were grown. X-ray diffraction data (a CAD4 diffractometer, MoK αradiation, 2140 F hkl, R=0.0251) were used to determine the structure of [Cd(4,4"-Bipy)(i-Bu2PS2)2]. The crystals are mono-clinic: a= 14.678(3) A, b= 11.866(2) A, c= 19.655(4) A, β = 102.17(3)°, V= 3346(1) A3, Z= 4, ρcalcd= 1.364 g/cm3, space group C2/c. The structure is built from linear polymeric chains arranged along the [010] direction. The coordination polyhedron of the Cd atom is a distorted octahedron (4S + 2N). The thermal properties of these compounds, studied both in air and in vacuo, allow one to use them for preparing CdS films by chemical precipitation from the gas phase.

Formation of extra complexes of aluminum tetraphenylporphine was studied by spectrophotometric titration. The effect of the nature of acido ligands on the stability of mixed-ligand complexes of aluminum tetraphenylporphine was determined. The stability constant (log Kst) of sterically unstrained complexes (Cl)Al(L)TPP and (OH)Al(L)TPP increases linearly with increasing basicity of the extra ligand (log KBH+); in the case of sterically distorted complexes (OAc)Al(L)TPP and (Acac)Al(L)TPP changes in log Kst and log KBH+ vary in the same direction. The geometries and energy characteristics of six-coordinate complexes of aluminum porphyrins were calculated quantum-chemically. The calculated enthalpies and Gibbs energies of formation of the complexes are consistent with the experiment. The possibility of the bidentate coordination of acetate and acetylacetonate in the porphyrin extra complexes was proved.

Bis(diisopropyldithiophosphato)zinc(II) Zni-PrO)2PS2 2 (I) possesses high volatility, which is useful for gas-chromatographic determination of zinc [1]. In the solid state the compound has a dimeric structure [2]. As shown for dimeric zinc(II) dialkyldithiocarbamates and tetrameric zinc(II) alkylxanthates, reactions of these chelates with nitrogen heterocycles [1,10-phenanthroline (Phen) or 2,2′-bipyridyl (2,2′-Bipy)] form volatile mixed-ligand compounds having a monomeric structure [3, 4]. It is interesting to synthesize and study the mixed-ligand compounds of chelate I with nitrogen-containing heterocycles. Synthesis of a mixed-ligand complex of this chelate with Phen was reported in [5, 6] but no structure determination was performed for the compound. We synthesized the compound ZnPhen[(i-PrO)2PS2]2 (II) using a slightly modified procedure [5], grew single crystals, and investigated its molecular and crystal structure.

The complexation of molybdenum with 2-hydroxy-5-chlorothiophenol (HCTP) in the presence of diphenylguanidine (DPG) was studied. The best conditions for the complex formation and extraction were determined. It was found that a mixed-ligand complex was formed in 2–4 M HC1. The best extractant was chloroform. The molar absorptivity of the mixed-ligand complex was found to be 2.5 x 104 (595 nm). The formation of a mixed-ligand complex of the composition Mo(V) : HCTP : DPG =1: 2 : 2 was shown.

Novel [CrIII(amp)(bipy)(Cl)] (1) (H2amp = N-(hydroxyphenyl)salicyldimine; bipy = 2,2′-bipyridyl) and [CrIII(app)(bipy)(Cl)]+ (2) (H2app = N-(hydroxyphenyl)pyridine-2-carboxaldimine; bipy = 2,2′-bipyridyl) complexes have been synthesized and characterized by physico-chemical methods. Complexes 1 and 2 have been employed as catalysts in the oxidation of both saturated and unsaturated hydrocarbons using tert-butylhydroperoxide (t-BuOOH). The significance of the results with respect to oxo-functionalization of C-H bonds both in unsaturated and saturated hydrocarbons is noted.

The synthesis, radiochemistry and biodistribution in mice of 99mTcO{[(CH3CH2)2NCH2CH2-N(CH2CH2S)2] (p-SPh-COOCH2CH3)}, I, are reported herein. Complex I forms by binding of (CH3CH2)2NCH2CH2N(CH2CH2SH)2 and p-HSPhCOOCH2CH3 ligands to reduced 99mTc using glucoheptonate (GH) as transfer ligand. Corroboration of structure with an authentic 99gTc sample is achieved by reverse phase high pressure liquid chromatography (RP-HPLC) adopting parallel radiometric and photometric detection modes. By incubation at 37°C with glutathione (GSH) in aqueous medium I tranforms to an hydrophilic compound, as shown by HPLC. Tissue distribution experiments reveal high uptake and retention of I in mice brain.

The crystal and molecular structure of the mixed-ligand complex Zn(S2CN(i-C4H9)2)2Phen was determined by single-crystal X-ray diffractometry (Syntex P21 diffractometer, CuKα radiation, 1738 F(hkl),R = 0.036). The crystals are triclinic, a =18.564(4), b =10.487(1), c =17.505(4) a, α = 84.04(2), Β =94.88(2), γ =90.87(2)‡;V =3377(1) a 3, Z = 4, dcalc = 1.287 g/cm3, space group C-1. The structure consists of monomeric molecules in which the zinc atom has a distorted octahedral environment (4S+2N).

Two types of mixed-ligand complexes, i.e. [M(phen)2 (dip)]2+ and [M(phen)(dip)2]2+ (M = iron(II) and nickel(II); phen = 1,10-phenanthroline and dip = 4,7-diphenyl-1,10-phenanthroline) have been prepared from their related tris-complexes, [M(phen)3]2+ by ligand substitution, and isolated by semi-preparative HPLC. Elemental and chromatographic analyses confirm the purity of the isolated complexes while u.v./vis and i.r. spectra were used to identify and characterize them. 1H-n.m.r. and room temperature Mossbauer spectra of the iron(III) complexes were also measured and the results are discussed. In addition, our preliminary results on hypochromicity in the MLCT band and circular dihroism (CD) emerging in the u.v./vis region upon addition of CT(calf thymus)-DNA to the racemic complexes indicated that the iron(II) mixed-ligand complexes interact with CT-DNA.

Synthetic procedures were developed and X-ray diffraction analysis was performed for two mixed-ligand compounds of europium(III) with diethyldithiocarbamate ions and 2,2′-bipyridyl (2,2′-Bipy) or 1,10-phenanthroline (Phen): Eu(S2CN(C2H5)2)3(2,2′-Bipy) (I) and Eu(S2CN(C2H5)2)3Phen (II). The structures of the complexes consist of discrete monomer molecules; the coordination polyhedron of Eu (EuN2S6 is a node) is a distorted dodecahedron.

The crystal structures of the mixed-ligand complexes of the heterospin bischelate bis [2,2,5,5-tetramethyl-l-oxyl-3-imidazoline-4-(3’,3’,3’-trifluoro-1’-propenyl-2’-oxiato)nickel(II) (NiL2) with iso-butanol and 1,4-butanediol NiL2(i-C4H9OH)2 and NiL2[HO(CH2)4OH], respectively, are determined. The crystal structure of the NiL2 complex with the normal butyl alcohol NiL2(n-C4H9OH)2 and the structure of CoL2[HO(CH2)4OH] are refined.

Mechanochemical synthesis of terbium quinolinates with nitrogen-containing neutral ligands involves several stages; no self-propagation reaction is observed. The resulting terbium(II) quinolinate exhibits paramagnetic properties.

Mixed-ligand complexes ZhPhen(i-Bu2Dtc)2, Zn(2,2′-Bipy)(i-Bu2Dtc)2, and Zn2(4,4′-Bipy)(i-Bu2Dtc)4, where i-Bu2Dtc=(i-C4H9)2NCS 2 − , have been synthesized. The structure of Zn2(4,4′-Bipy)(i-Bu2Dtc)4 was determined by X-ray diffraction analysis; it consists of centrosymmetric binuclear molecules with trigonal-bipyramidal coordination of the central Zn atom. When heated in vacuum, the compounds quantitatively sublimate or evaporate. Thermal decomposition of the compounds in air (350°C) gives α-ZnS.