Syntheses, Supramolecular Structures and Antibacterial Activities of Five Helical Transition Complexes with 5-Chloro-1-phenyl-1H-pyrazole-3,4-dicarboxylic Acid

Five new transition metal complexes [Cu(HL)₂(H₂O)₂] ( 1 ), [Cu(HL)₂(phen)] ( 2 ), [Cu(HL)₂(H₂O)]₂(4,4′‐bipy) ( 3 ), [Zn(HL)₂(H₂O)₂]·(4,4′‐bipy) ( 4 ), [Ag(HL)(4,4′‐bipy)]_n ( 5 ), (H₂L=5‐chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid, phen=1,10‐phenanthroline; 4,4′‐bipy=4,4′‐bipyridine) have been synthesized and characterized. Complexes 1 , 2 and 4 exhibit monomeric structures, 3 shows a dinuclear structure, 5 displays 1D chain structure, and all extend to 3D supramolecular network via rich hydrogen bonds. Complexes 1 , 2 , 3 , 5 comprise single helical chains, while complex 4 generates quadruple‐stranded helical chains. Furthermore, the antibacterial activities of the titled complexes against bacterial species, three Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis and Candida albicans) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were studied and compared to the activities of free ligands by using the microdilution method.     

Tetranuclear and One‐dimensional Cobalt Complexes with 5‐tert‐Butyl Isophthalic Acid and Chelating Neutral Ligands

Two new Co^II coordination polymers [Co₄(tbip)₄(bipy)₄(H₂O)₄] ( 1 ) and [Co(tbip)(phen)(H₂O)] · H₂O ( 2 ) (H₂tbip = 5‐tert‐butyl isophthalic acid, bipy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Compound 1 is a tbip‐bridged tetranuclear cobalt(II) complex, which is further linked by hydrogen bonds to form a supramolecular network. Compound 2 shows a tbip‐bridged linear chain structure, which is extended by hydrogen bonds to generate a double chain. Magnetic measurements show that there are weak ferromagnetic interactions between the adjacent Co^II ions in 1 .     

Synthesis,Characterization, and Thermostability of Four Novel Cadmium(II) Coordination Polymers with Mixed Ligands

Four novel mixed‐ligand complexes were obtained from the reaction of maleic acid, diimine chelating ligands and Cd(OH)₂ or CdO in a mixed solvent of water and methanol. The complexes were characterized by IR spectroscopy, elemental analysis, and single‐crystal X‐ray diffraction. The results show that all the four complexes are coordination polymers. [Cd(phen)(H₂O)(male)]_n · 2nH₂O ( 1 ) and [Cd(bipy)(H₂O)(male)]_n · 2nH₂O ( 2 ) (male = maleate; phen = 1, 10‐phenanthroline, bipy = 2, 2′‐bipyridine) are isomorphic, and the asymmetric unit is constructed by one Cd^II atom, a maleate group, a diimine ligand and two crystal water molecules. Each maleate group links two Cd^II atoms in a bis(bidentate) chelating mode, resulting in a 1D helical chain. Within [Cd(phen)(H₂O)₂(male)]_n · 2nH₂O ( 3 ), the maleate group bridges two Cd^II atoms in a bis(monodentate) chelating mode into a 1D helical chain along the [100] direction. The helical chain is decorated by phen groups alternatively at the two sides, and each phen plane of one chain is inserted in the void space between two adjacent phen ligands from an adjacent chain, resulting in a double zipper‐like chain. The asymmetric unit of [Cd₂(phen)₂(male)₂]_n ( 4 ) contains a Cd^II cation, one phen molecule, and a maleate group, and one bridging maleate group links three Cd^II atoms resulting in a 2D layer extending in [011] plane. The 2D networks are constructed by four kinds of rings formed by the central metal atom and maleate dianion. The thermostabilities of the four complexes were investigated.     

Structural Diversity of Metallosupramolecular Assemblies from Cu(phen)2+ (phen = 1,10‐Phenanthroline) Building Blocks and 4,4′‐Bipyridine

Attempts to crystal engineer metallosupramolecularcomplexes from Cu(phen)²⁺ building blocks and the prototypical,rod‐like, exo‐bidentate ligand 4,4′‐bipyridine (4,4′‐bipy) by layering techniques are described. Reactions of Cu(phen)²⁺ (phen = 1,10‐phenanthroline) with 4,4′‐bipy in the presence of NO₃^– counterions yielded two distinct, discrete, dinuclear, C_i symmetric, dumbbell‐typecomplexes, [{Cu(NO₃)₂(phen)}₂(4,4′‐bipy)] ( 1 ) and [{Cu(NO₃)(phen)(H₂O)}₂(4,4′‐bipy)](NO₃)₂ ( 2 ), depending upon the mixture of solvents used for crystallization. In compound 1 , a mono‐ and a bidentate nitrato group coordinate to Cu²⁺, whereas in 2 the monodentate nitrato groups are replaced by aqua ligands, which introduce additional hydrogen‐bond donor functionality to the molecule. The crystal structure of 1 was determined by single‐crystal X‐ray analysis at 296 and 110 K. Upon cooling, a disorder‐order transition occurs, with retention of the space group symmetry. The crystal structure of 2 at room temperature was reported previously [Z.‐X. Du, J.‐X. Li, Acta Cryst. 2007 , E63, m2282]. We have redetermined the crystal structure of 2 at 100 K. A phase transition is not observed for 2 , but the low temperature single‐crystal structure determination is of significantly higher precision than the room temperature study. Both 1 and 2 are obtained phase‐pure, as proven by powder X‐ray diffraction of the bulk materials. Crystals of [Cu(phen)(CF₃SO₃)₂(4,4′‐bipy) · 0.5H₂O]_n ( 3 ), a one‐dimensional coordination polymer, were obtained from [Cu(CF₃SO₃)₂(phen)(H₂O)₂] and 4,4′‐bipy. In 3 , Cu(phen)²⁺ corner units are joined by 4,4′‐bipy via the two vacant cis sites to form polymeric zig‐zag chains, which are tightly packed in the crystal. Compounds 1 – 3 were further studied by infrared spectroscopy.     

Novel Copper(II) Thiodibenzoic Acid Coordination Polymers by in situ Extrusion of Sulfur from 2,2′‐Dithiodibenzoic Acid and the Unique Oxidation of Disulfide to Sulfate

Slow diffusion reaction of 2,2′‐dithiodibenzoic acid (dtdb) with CuCl₂ in the presence of N‐donor ligands results in the formation of different coordination polymers where both S–S and C–S scission and oxidation of S is observed. X‐ray diffraction analysis of [Cu(tdb)(phen)(H₂O)]₂ · 2H₂O.2DMF] ( 1 ), [Cu(tdb)(py)₂(H₂O)]₂ ( 3 ), and [Cu(tdb)(bipy)(H₂O)]₂ · 0.5H₂O ( 4 ) (tdb = thiodibenzoic acid, phen = phenanthroline, py = pyridine, bipy = 2,2′‐bipyridine) show that the metal ions are coordinated to the carboxylate oxygen atoms of the in situ generated tdb ligand in a monodenate fashion. In [Cu(phen)(SO₄)₂(H₂O)₂]_n ( 2 ) and [Cu(bipy)(SO₄)₂(H₂O)₂]_n ( 5 ), the sulfur is oxidized to sulfate ions prior to coordination with the metal. Complex 1 has a dimeric structure with π–π interactions between the phen ligands, whereas 3 and 4 form 1D polymeric chains.     

Three Novel Mixed‐ligand Cadmium(II) Sulfonates with Aza‐aromatic Skeltons as Co‐ligands

To survey the influence of aza‐aromatic co‐ligands on the structure of Cadmium(II) sulfonates, three Cd(II) complexes with mixed‐ligand, [Cd^II(ANS)₂(phen)₂] ( 1 ), [Cd^II(ANS)₂(2,2′‐bipy)₂] ( 2 ) and [Cd^II(ANS)₂(4,4′‐bipy)₂]_n ( 3 ) (ANS = 2‐aminonaphthalene‐1‐sulfonate; phen = 1,10‐phenanthroline; 2,2′‐bipy = 2,2′‐bipyridine; 4,4′‐bipy = 4,4′‐bipyridine) were synthesized by hydrothermal methods and structurally characterized by elemental analyses, IR spectra, and single crystal X‐ray diffraction. Of the three complexes, ANS consistently coordinates to Cd²⁺ ion as a monodentate ligand. While phen in 1 and 2,2′‐bipy in 2 act as N,N‐bidentate chelating ligands, leading to the formation of a discrete mononuclear unit; 4,4′‐bipy in 3 bridges two Cd^II atoms in bis‐monodentate fashion to produce a 2‐D layered network, suggesting that the conjugate skeleton and the binding site of the co‐ligands have a moderate effect on molecular structure, crystal stacking pattern, and intramolecular weak interactions. In addition, the three complexes exhibit similar luminescent emissions originate from the transitions between the energy levels of sulfonate anions.     

Synthesis,Structure and Noncovalent Interactions Palladium（Ⅱ）Complexes with N—Benzoyl—β—phenylalaniate Dianion and Aromatic Diimine

Two palladium(II) complexes, [Pd(bipy)(BzPhe‐N,O)] and [Pd(phen)(BzPhe‐N,O)]·4H₂O were synthesized by reactions between Pd(bipy)Cl₂ and BzPheH₂ (N‐benzoyl‐β‐phenylalanine), Pd(phen) Cl₂ and BzPheH₂ in water at pH‐9, with their structures determined by X‐ray diffraction analysis. The Pd atom is coordinated by two nitrogen atoms of bipy (or phen), the deprotonated amido type nitrogen atom and one of the carboxylic oxygens of BzPhe (BzPhe = N‐benzoyl‐β‐phenylalaninate dianion). In the complex [Pd(phen) (BzFne‐N,O)] · 4H₂O, the side chain of phenylalanine is located above and approximately parallels to the coordination plane. Both the aromatic‐aromatic stacking interaction between the phenyl ring of phenylalanine and phen, and the metal ion‐aromatic interaction between the phenyl ring of phenylalanine and Pd(II) were observed. [Pd(bipy)(BzPhe‐N,O)] has the phenylalanyl side chain oriented outwards from the coordination plane, which is mainly due to the interaction between the carbonyl oxygen atom of the amido group and the phenyl ring of phenylalanine. The reason for the different orientation of phenylalanyl side chain in the complexes was suggested.     

New Examples of Metal Coordination Architectures of 3,3′,4,4′‐Biphenyltetracarboxylic Acid – Syntheses,Crystal Structures,and Physical Properties

Four new metal‐organic frameworks [Cu₂(2,2′‐bipy)₂(ox)(H₂O)₂]·(H₂bptc) ( 1 ), [Cu(bptc)_0.5(phen)(H₂O)]·H₂O ( 2 ), Co₂(bptc)(bmb)_1.5 ( 3 ) and [Cd₂(bptc) (bmb)]·3H₂O ( 4 ) (H₄bptc = 3,3′,4,4′‐biphenyltetracarboxylic acid, ox = oxalate, phen = 1,10‐phenanthroline, 2,2′‐bipy = 2,2′‐bipyridine and bmb = 4,4′‐bis((1H‐imidazol‐1‐yl)methyl)biphenyl), were obtained by reactions of the corresponding metal salts with H₄bptc and N‐containing auxiliary ligands and their structures were determined by single‐crystal X‐ray diffraction. The results reveal that 1 has a 0‐D structure consisting of discrete ionic entities, while 2 features a 1‐D ladder structure. Additionally, there exist π‐π stacking and intermolecular hydrogen‐bonding interactions in 1 and 2 , respectively, forming 3‐D supramolecular structures. In 3 ‐ 4 , undulating 2‐D metal‐bptc layer structures are formed with two different coordination modes of bptc carboxylate groups, respectively, which are further extended by bmb into 3‐D structures. Magnetic properties of 1 and 3 have been studied. The photoluminescence property of 4 has also been investigated. Moreover, nonlinear optical measurements showed that 4 displayed a second‐harmonic‐generation (SHG) response of 0.7 times of that for urea.     

Effective catalytic oxidation of alcohols and alkenes with monomeric versus dimeric manganese(II) catalysts and t‐BuOOH

Two new Mn(II) complexes, [Mn(C₆H₅COO)(H₂O)(phen)₂](ClO₄)(CH₃OH) ( 1 ) and [Mn₂(μ‐C₆H₅COO)₂(bipy)₄]?2(ClO₄) ( 2 ) (phen = 1,10‐phenanthroline; bipy = 2,2′‐bipyridine), were synthesized and characterized using UV–visible and infrared spectroscopies and single‐crystal X‐ray diffraction analyses. Complexes 1 and 2 have six‐coordinate octahedral geometry around the Mn(II) centre. Complex 1 is a monomer and consists of a deprotonated monodentate benzoate ligand together with two neutral bidentate amine ligands (phen) and a water molecule. Complex 2 has a dinuclear structure in which two Mn(II) ions share two carboxylate groups, adopting a two‐atom bridging mode, and two chelated bipy ligands. Both complexes catalyse the oxidation of alcohols and alkenes in a homogeneous catalytic system consisting of the Mn(II) complex and tert‐butyl hydroperoxide (TBHP) in acetonitrile. The system yields good to quantitative conversions of various alkenes and alcohols, such as styrene, ethylbenzene and cyclohexene to their corresponding ketones, and primary alcohols and 1‐octanol, 1‐heptanol, cyclohexanol, benzyl alcohols and cinnamyl alcohol to their corresponding aldehydes and carboxylic acids. Complexes 1 and 2 exhibit very high activity in the oxidation of cyclohexene to cyclohexanone (ca 80% selectivity) as the main product (ca 94% conversion in 1 h) and of cinnamyl alcohol to cinnamaldehyde (ca 64% selectivity) as the main product (ca 100% conversion in 0.5 h) with TBHP at 70°C in acetonitrile. In addition, optimum reaction conditions were also determined for benzyl alcohol with complexes 1 and 2 and TBHP. Copyright © 2016 John Wiley & Sons, Ltd.     

The chemistry of pyridine thiols and related ligands, Part 5. Synthesis and spectroscopy of nickel(II) and copper(II) complexes containing 1-oxopyridine-2-thione and 2,2′-bipyridine or 1,10-phenanthroline

Summary Reactions of bis(1-oxopyridine-2-thione) Ni^II or Cu^II with 2,2-bipyridine (bipy) or 1,10-phenanthroline (phen) yield complexes of stoichiometry: Ni(C₅H₄NOS)₂L {L = bipy, two isomers: (1) and (2), L = phen, one isomer (3)} and Cu(C₅H₄NOS)₂(phen)·0.75CHCl₃ (4). The spectroscopy (i.r., u.v.-vis., e.s.r.) and magnetism studies of the above complexes are described. On the basis of conductivity, the Cu^II-phen complex has been formulated as [Cu(C₅H₄NOS)(phen)₂][Cu(C₅H₄NOS)₃]·1.5CHCl₃ (4). The vis. absorption spectra support similar octahedral structures for the minor bipy isomer (2) and for the Ni^II-phen complex [(3)], whereas the major isomer [(1)] has a different structure. The e.s.r. spectrum of the Cu^II-phen complex (4) is commensurate with an elongated octahedral structure. New methods for the preparation and spectroscopy of M(C₅H₄NOS)₂ (M = Mn, Ni, Cu or Zn) compounds have been investigated.     

Hydrothermal synthesis, crystal structure and luminescence of four novel metal-organic frameworks

Using the principle of crystal engineering, four novel metal-organic coordination polymers, {[Cd₁(nic)2(H₂O)]2[Cd₂(nic)2(H₂O)2]}_n (1), [Cd₂(fma)2(phen)2]_n (2), [Cd(fma)(bipy)(H₂O)]_n (3) and [Zn(mal)(bipy)·3H₂O]_n (4) (nic=nicotinate, fma=fumarate, mal=malate, phen=phenanthroline, bipy=2,2′-bipyridine) have been synthesized by hydrothermal reaction of M(CH₃COO)2·2H₂O (M=Zn, Cd) with nicotinic acid, fumaric acid and cooperative L (L=phen, bipy), respectively. X-ray analysis reveals that complex 1 possesses an unprecedented two-dimensional topology structure constructed from three-ply-like layers, complex 2 is an infinite 2D undulating network, complex 3 is a 1D zigzag chain and complex 4 belongs to a 1D chain. The results indicate a transformation of fumarate into malate during the course of hydrothermal treatment of complex 4. The photophysical properties have been investigated with luminescent excitation and emission spectra.     

Synthesis,crystal structures and properties of 3d–4f heterometallic coordination polymers,using [Fe(bipy)(CN)4]2− as a versatile building block

Two novel cyano-bridged lanthanide-transition-metal complexes, K[Fe(bipy)(CN)_{4 2}Tb(H₂O)₄]·3H₂O (1) and [Fe(bipy)(CN)₄Sm(phen)(NO₂)(H₂O)₂]·H₂O (2) (bipy = 2.2-bipyridine; phen = 1, 10-phenanthroline), have been prepared and structurally characterized. Complex (1) possesses a cyano-bridged two-dimensional (2D) honeycomb-like structure with centrosymmetric [Fe^II(bipy)(CN)_{4 2}Tb^III(H₂O)₄]^– anions, potassium cations, and water of crystallization molecules. Complex (2) consists of a cyano-bridged one-dimensional (1D) ladder structure with neutral [Fe^II(bipy)(CN)₄Sm^III(phen)(NO₂)(H₂O)₂] and water of crystallization molecules. The magnetic properties of (1) have been investigated in the 2.0–300 K range. The data for (1) reveal that magnetic interactions between Tb³⁺ ions through the low-spin Fe²⁺ ions are negligible.     

Synthesis,Structures, and Fluorescent Properties of Three Cobalt‐Based Coordination Polymers with a Rigid Tripodal Carboxylate Ligand

Three cobalt(II) coordination polymers, [Co₂(tatb)₂(2,2′‐bipy)₂ (H₂O)₂ · DMA · 2H₂O] ( 1 ), [Co₂(tatb)₂(1,10‐phen)₂(H₂O)₂ · 2H₂O] ( 2 ) and [Co(tatb)(1,3‐dpp) · H₂O] ( 3 ) (H₃tatb = 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tribenzoic acid; 2,2′‐bipy = 2,2′‐bipyridyl; 1,10‐phen = 1,10‐phenanthroline; 1,3‐dpp = 1,3‐bis(pyridin‐4‐yl)propane), were synthesized solvothermally and characterized by single‐crystal and powder X‐ray diffraction (PXRD), as well as IR spectroscopy. Complexes 1 and 2 exhibit 1D double‐chain structures, which further connect into interesting 3D networks by hydrogen bond and strong π–π interactions. Complex 3 possesses 2D 4⁴‐sql topology, which is packed parallel in an AA fashion. Moreover, thermal stability properties and photoluminescence properties of 1 , 2 and 3 were also investigated.     

Synchronizing Substrate Activation Rates in Multicomponent Reactions with Metal–Organic Framework Catalysts

A study on the influence of the cation coordination number, number of Lewis acid centers, concurrent existence of Lewis base sites, and structure topology on the catalytic activity of six new indium MOFs, has been carried out for multicomponent reactions (MCRs). The new indium polymeric frameworks, namely [In₈(OH)₆(popha)₆(H₂O)₄]?3 H₂O ( InPF‐16 ), [In(popha)(2,2′‐bipy)]?3 H₂O ( InPF‐17 ), [In₃(OH)₃(popha)₂(4,4′‐bipy)]?4 H₂O ( InPF‐18 ), [In₂(popha)₂(4,4′‐bipy)₂]?3 H₂O ( InPF‐19 ), [In(OH)(Hpopha)]?0.5 (1,7‐phen) ( InPF‐20 ), and [In(popha)(1,10‐phen)]?4 H₂O ( InPF‐21 ) (InPF=indium polymeric framework, H₃popha=5‐(4‐carboxy‐2‐nitrophenoxy)isophthalic acid, phen=phenanthroline, bipy=bipyridine), have been hydrothermally obtained by using both conventional heating (CH) and microwave (MW) procedures. These indium frameworks show efficient Lewis acid behavior for the solvent‐free cyanosilylation of carbonyl compounds, the one pot Passerini 3‐component (P‐3CR) and the Ugi 4‐component (U‐4CR) reactions. In addition, InPF‐17 was found to be a highly reactive, recyclable, and environmentally benign catalyst, which allows the efficient synthesis of α‐aminoacyl amides. The relationship between the Lewis base/acid active site and the catalytic performance is explained by the 2D seven‐coordinated indium framework of the catalyst InPF‐17 . This study is an attempt to highlight the main structural and synthetic factors that have to be taken into account when planning a new, effective MOF‐based heterogeneous catalyst for multicomponent reactions.     

Two Discrete Lanthanum(III) Complexes with Bulky Aromatic Mixed Ligands: Syntheses,Crystal Structures and Fluorescent Properties

Two discrete lanthanide complexes with bulky aromatic mixed‐ligands, {[La₂(na)₆(phen)₂]·[La₂(na)₆(phen)₂]} ( 1 ) and [La₂(na)₆(2,2′‐bipy)₂] ( 2 ) (Hna = 1‐naphthoic acid, phen = 1,10‐phenanthroline, and 2,2′‐bipy = 2,2′‐bipyridine), have been synthesized under hydrothermal conditions and fully characterized by single‐crystal X‐ray crystallography, IR, elemental analysis, TG‐DTA and fluorescence spectra. Structure determination reveals that 1 contains two separate binuclear [La₂(na)₆(phen)₂] units, in which both crystallographically La^III ions are nine‐coordinated with tricapped trigonal prism polyhedron for La1 and a distorted monocapped square antiprism arrangement for La2; whereas 2 has a binuclear structure bridged by carboxylate groups of four na anions. Due to the introduction of bulky aromatic ligands, non‐classical C–H···O H–bonds and π – involved stacking interactions become the dominantly driving forces for the supramolecular structure. The two solid complexes exhibit intense fluorescent emissions at room temperature resulted from the ligand‐to‐metal charge transfer.     

Distinct Chain/Layer Structures in Silver(I) Compounds: Synthesis,Structures, and Photoluminescent Properties

Two new hybrid inorganic‐organic compounds with different chain/layer structures, [Ag(bipy)]_n · n(Hdpa) · n(DMF) · n(H₂O) ( 1 ) and [Ag(dpa)_0.5(bix)_0.5]_n ( 2 ) [H₂dpa = diphenic acid, bipy = 4, 4′‐bipyridine, bix = 4, 4′‐bis(imidazol‐1‐ylmethyl)benzene, DMF = N,N′‐dimethylformamide] were successfully synthesized and characterized by elemental analysis, IR spectroscopy, and powder X‐ray diffraction. Single X‐ray analysis reveals that compound 1 is a one‐dimensional (1D) supramolecular double chain structure constructed by the combination of coordination bonds, hydrogen bonds, weak Ag ··· O and argentophilic interactions, compound 2 is a two‐dimensional (2D) undulated layer structure constructed by coordination bonds, weak Ag ··· O and argentophilic interactions. Moreover, the photoluminescent properties of the two compounds were also investigated in the solid state at room temperature.     

Hydrolytic Ring Opening Reactions of Pyromellitic Dianhydride for Divalent Transition Metal Carboxylate Complexes

The hydrolytic ring opening reactions of pyromellitic dianhydride is an effective method to prepare transition metal carboxylate complexes. In this paper, two dinuclear complexes [Ni₂(2,2′‐bipy)₂(btec)(H₂O)₆] · 2H₂O ( 1 ) and [Cd₂ (phen)₄(H₂O)₂(H₂btec)] · H₂btec · 2H₂O ( 2 ) (H₄btec = 1,2,4,5‐benzenetetracarboxylic acid, phen = 1,10‐phenanthroline, and 2,2′‐bipy = 2,2′‐bipyridine) were synthesized by slow diffusion methods and their structures were determined byX‐ray structure analysis. In both structures metal atoms are in distorted octahedral environments and they are linked by bis‐monodentately coordinated 1,2,4,5‐benzentetracarboxylate ligands as bridging units. The crystalline compounds, which are insoluble in water as well as common organic solvents, have been characterized in the solid‐state by elemental analysis, thermogravimetric analysis, IR, and diffuse reflectance UV/Visspectroscopy. Moreover, the study of the physical properties of complex 2 demonstrates that it exhibits blue fluorescence emission in the solid state at room temperature.     

Formation and Structural Characterization of Metal Complexes derived from Thiosalicylic Acid

The formation and structural aspects of some metal complexes of thiosalicylic acid (TSA) were studied. The μ‐bridging tetra‐coordinated Ru complex, [Ru(C₆H₄(CO₂)(μ‐S)(H₂O)]₂ ( 1 ) was formed by hydrothermal reaction of TSA with RuCl₃. The complexes [M(dtdb)(phen)(H₂O)]_n ( 2 – 4 ) (M = Zn^II, Co^II, Ni^II, dtdb = 2,2′‐dithiodibenzoate anion, phen = 1,10‐phenanthroline) were obtained by the slow diffusion technique and the in situ S–S bond formation was confirmed by elemental, spectral and X‐ray analysis. Reaction of TSA with CuCl₂ and 2,2′‐bipyridine (bipy) under the slow diffusion technique yielded the dimer [Cu(tdb)(bipy)] ( 5 ) (tdb = thiodibenzoic acid), where the in situ generation of 2,2′‐thiodibenzoic acid was observed.     

Complexes of Cu2(μ‐OAc)4(H2O)2 with 1,10‐Phenanthroline and Comparison with those of 2,2′‐Bipyridine. Crystal Structure of the Dimer [Cu(OAc)2(phen)](μ‐H2O)

The two complexes of composition Cu₂(OAc)₄(phen)(H₂O)₂ ( 1 ) andCu₂(OAc)₄(phen)₂(H₂O) ( 2 ) have been synthesized and characterized by chemical analysis and IR and electronic spectroscopies. Compound 2 has the structure of a dimer with a phenanthroline molecule and two monodentate acetate groups coordinated to each copper atom and a water molecule as the only bridging ligand between them. Each copper atom has a distorted square‐planar pyramidal coordination, determined by two oxygen atoms at 1.94(3) and 1.959(3) Å, two nitrogen atoms at 2.023(4) Å and the oxygen atom of the bridging water molecule at 2.289(2) Å. The distance between the two copper atoms is of 4.29 Å and the angle Cu(1)‐O(3)‐Cu(1A) 139.2(2)°. The water molecule is involved in two intramolecular hydrogen bonds with non coordinated oxygen atoms. The distance between the molecules of phenanthroline is 3.75 Å. Magnetic and EPR results for Cu₂(OAc)₄(phen)(H₂O)₂ ( 1 ), Cu₂(OAc)₄(phen)₂(H₂O) ( 2 ), Cu₂(OAc)₄(bipy) ( 3 ) and Cu₂(OAc)₄(bipy)₂(H₂O)₂ ( 4 ) have been analysed and compared. For 1 and 3 an antiferromagnetic dimer unit [Cu₂(μ‐OAc)₄] with 2J = ?325 and ?292 cm^?1, respectively, and other two copper atoms without significant magnetic interaction are present. Triplet signals are detected in the EPR spectra. In 2 and 4 there is no practically magnetic exchange and the orthorhombic signals are observed in the EPR spectra.     

Three Dicyanidometallate(I)‐based Complexes Incorporating Hydrogen‐bonding, π–π Packing and d10–d10 Interactions with Auxiliary 2,2′‐Bipyridyl‐like Ligands

To investigate the influence of the non‐covalent interactions, such as hydrogen‐bonding, π–π packing and d¹⁰–d¹⁰ interactions in the supramolecular motifs, three cyanido‐bridged heterobimetallic discrete complexes {Mn(bipy)₂(H₂O)[Ag(CN)₂]}[Ag(CN)₂] ( 1 ), {Mn(phen)₂(H₂O)[Au(CN)₂]}₂[Au(CN)₂]₂ · 4H₂O ( 2 ), and {Cd(bipy)₂(H₂O)[Au(CN)₂]}[Au(CN)₂] ( 3 ) (bipy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline), which are based on dicyanidometallate(I) groups with 1:2 stoichiometry of metal ions and 2,2′‐bipyridyl‐like co‐ligands were synthesized and structurally characterized. In compound 1 , hydrogen bonding and π–π interactions governed the supramolecular contacts. In compound 2 , the incorporation of aurophilic, hydrogen bonding and π–π interactions result in a 3D supramolecular network. In compound 3 , hydrogen bonding and π–π stacking interactions result in a 2D supramolecular layer. In the three complexes, hydrogen‐bonding, π–π packing and/or d¹⁰–d¹⁰ interactions can play important roles in increasing the dimensionality of supramolecular assemblies.