Syntheses and characterization of ferrocenylthiocarboxylate-containing coordination compounds for nonlinear optics

Four metal-organic coordination compounds containing ferrocenylthiocarboxylate components, [Cd₂(η²-SOCFc)₂(η¹-μ₂-SOCFc)₂(4,4′-bpy)]_n (1), [Cd(SOCFc)₂(tmp)]_n (tmp = 4,4′-trimethylene-dipyridine) (2) [Zn(SOCFc)₂(2,2′-bpy)] (3), and {[Hg(SOCFc)₂(phen)] · (0.5CH₃OH)} (4) (Fc = (η⁵-C₅H₅)Fe(η⁵-C₅H₄)), have been prepared in search of good nonlinear optical (NLO) materials. Investigation of the NLO properties shows that Hg-containing compound 4 exhibits very strong third-order NLO absorptive and refractive effects. The NLO absorptive coefficient α₂ value (2.11 × 10⁻¹⁰ m W⁻¹) is larger than those of all the reported ferrocenylcarboxylate-containing coordination compounds and comparable to the well-performing Hg-containing complexes. Additionally, we further analyzed their NLO behaviors through studying electrochemical properties of the four compounds.     

1D coordination polymers of Cu(II) and Cu(II) dimers with a dicyanomethanide ligand

Several new 1D coordination polymers have been synthesised using the anionic ligand carbamoyldicyanomethanide, C(CN)₂(CONH₂)⁻ (cdm). The polymeric complexes [Cu(cdm)₂(py)₂]·2MeOH (1), [Cu(cdm)₂(4-Etpy)₂]·2MeOH (2), [Cu(cdm)₂(3,5-Me₂pzH)₂]·2MeOH (3) and [Cu(cdm)₂(3-HOCH₂py)₂]·2MeOH (4) (py = pyridine; 3,5-Me₂pzH = 3,5-dimethylpyrazole) contain Cu(II) atoms bridged by μ₂-(N,N′) cdm ligands between equatorial and axial coordination sites. The use of monodentate co-ligands brings about polymeric products, in contrast to the use previously of chelating co-ligands which facilitate the formation of discrete products. These 1D polymeric complexes are connected by hydrogen bonding between the amide functionalities and the lattice solvent. In the structures of 3 and 4 the neutral ligands also contain hydrogen bond donor groups that supplement the amide ring motif. Two other complexes have been obtained that are polymeric chains of alkoxide-bridged Cu(II) dimers. The complexes [Cu(cdm)(MeO)(2-amp)] (5) and [Cu(cdm)(dmap)] (6) (2-amp = 2-(aminomethyl)pyridine and dmap = dimethylaminopropoxide) are remarkably similar despite the different ligands that they contain. Bridging between dimers is via μ₂-(N,O) cdm ligands, consequently altering the nature of the hydrogen bonding between adjacent chains compared to the simple polymeric species 1–3.     

Metal-assisted transformation of N-benzoyldithiocarbazate to 5-phenyl-1,3,4-oxadiazole-2-thiol in the presence of ethylenediamine,and its first row transition metal complexes

The reaction of metal complexes of the type [M(HL)Cl] or [M(HL)₂] [where M = Cu(II), Ni(II), Mn(II), Co(II) and Zn(II) and H₂L = N-benzoyldithiocarbazate] with an excess of ethylenediamine (en) in CHCl₃–MeOH medium leads to ring closure by desulfurisation to yield unique mixed-ligand complexes 1–4, [Cu(en)₂](pot)₂(pot = 5-phenyl-1,3,4-oxadiazole-2-thiol), [M(en)₂(pot)₂] [M = Ni(II), Mn(II)] and [Zn(en)(pot)₂]. The metal complexes have been characterized by various physicochemical methods. The molecular structure of [Cu(en)₂](pot)₂ has been determined by a single crystal X-ray diffraction study. In the centrosymmetric unit of [Cu(en)₂](pot)_2, the metal ion has a square planar arrangement of four symmetry related N-atoms of two en groups and is ionically bonded to two pot anions. Weak interaction studies on the complex reveal the presence of a hydrogen-bonded network in the molecule involving non-coordinating donor atoms of the pot anion with en resulting in the formation of an extended three-dimensional network. The arrangement of the [Cu(en)₂]²⁺ units, at a dihedral angle of 49.43° to pot⁻, provides a network of intermingled chains leading to a π–π stacked 3-dimensional framework.     

Di- and trinuclear olato-bridged copper(II) compounds of 3,7-bis(3-olatopropyl)-1,3,5,7-tetraazabicyclo[3,3,1]nonane (protan); the structures of [{Cu(μ-protan)}2Cu](ClO4)2·H2O and [{Cu(μ-protan)}Cu(OH)2](ClO4)2·0.5(EtOH)

A compound with a linear trinuclear copper(II) cation, [Cu₃(μ-protan)₂](ClO₄)₂·H₂O (protanH₂ = 3,7-bis(3-hydroxypropyl)-1,3,5,7-tetraazabicyclo[3,3,1]-nonane) is formed by reaction of copper(II) perchlorate, 3-aminopropanol, ammonia and methanal. The cation is approximately centrosymmetrical with Cu?Cu = 2.9870(5) and 2.9485(5) Å. The terminal copper(II) ions are coordinated by nitrogen atoms 3 and 7 of the tetraazabicycle (Cu–N_mean = 2.021(5) Å) and the two oxygen atoms of the 3,7-bis(3-olatopropyl) substituents (Cu–O_mean = 1.911(3) Å), which also act as bridging groups to the central copper(II) ion (Cu–O_mean = 1.926(4) Å). The cation is both helically twisted (dihedral angle N3?N7?N3′?N7′ = 20(1)°) and bent (angle Cu?Cu?Cu = 171(1)°). The copper(II) ions have tetrahedrally twisted square planar primary coordination, with perchlorate ion oxygen atoms weakly coordinated axially to the two terminal copper(II) ions, on opposite sides of the “plane” of the molecule, while the central copper(II) ion is weakly coordinated axially by a water molecule, with all axial Cu–O distances ca. 2.9 Å. One N·CH₂·CH₂·CH₂·O chelate ring for each protan²⁻ ligand shows conformational disorder and the perchlorate ions show rotational disorder. Partial hydrolysis of the protan²⁻ compound gave a compound [{Cu(μ-protan)}Cu(OH)₂](ClO₄)₂·0.5(EtOH) which has a dinuclear cation, with one copper(II) ion in square-planar coordination by tetradentate protan²⁻ and the other in square-planar coordination by the two bridging oxygen atoms of the protan²⁻ ligand and by two hydroxide ions, with Cu?Cu = 3.045(1) Å. With differing mole ratios of the same reactants compounds of the dinuclear cation [{Cu(μ-pta)}₂]²⁺ (ptaH = 3(3-hydroxypropyl)-1,3,5,7-tetraazabicyclo[3,3,1]nonane) are formed.     

Magnetic single-component molecular conductors exhibiting strong π-d interactions

Single-component molecular conductors [M(tmdt)₂] (tmdt = trimethylenetetrathiafulvalenedithiolate; M = Ni, Au, Pt, Cu), exhibit a variety of electromagnetic properties, which originate from the differences of the metal’s d-orbitals role in the band structure formation. The [Au(tmdt)₂] crystal undergoes an antiferromagnetic transition at 110 K, while maintaining a metallic state at lower temperatures. The Au analog has a high magnetic transition temperature as compared to traditional magnetic molecular conductors due to the strong three-dimensional (3-D) structure and the contribution of the metal d-orbitals. The single-component molecular conductor, [Cu(tmdt)₂], with π- and d-like frontier orbitals is isostructural with other metallic [M(tmdt)₂] systems (M = Ni, Pt, Au). The Cu(tmdt)₂ molecule is planar, which strikingly contrasts the tetrahedral coordination of Cu(dmdt)₂ (dmdt = dimethyltetrathiafulvalenedithiolate) with similarly extended TTF type ligands. Interestingly, unlike other [M(tmdt)₂] with metallic behavior, [Cu(tmdt)₂] shows semiconducting behavior at room temperature (σ(RT) = ∼7 S cm⁻¹). The RT conductivity increased linearly with increased pressure to 110 S cm⁻¹ at 15 kbar despite the compressed pellet sample. The magnetic susceptibility indicates one-dimensional (1-D) Heisenberg behavior with J = 117 cm⁻¹ and shows antiferromagnetic ordering at 13 K. The [Cu(tmdt)₂] is a new multi-frontier π-d system, which introduces a d(σ)-type frontier orbital around the Fermi level of the π-like metal bands.     

Unprecedented μ-1,2-bis(monodentate) coordination mode of croconate dianion (C5O5): Synthesis and crystal structures of manganese- and copper-based coordination polymers

Two new coordination polymers {[Mn₂(BPP)₂(C₅O₅)₂(OH₂)₄]·3H₂O}_n (1) and {[Cu₄(BPP)₄(C₅O₅)₄]·8H₂O}_n (2) [BPP = 1,3-bis(4-pyridyl)propane and C₅O₅²⁻ = croconate anion] were synthesized and characterized by thermal analysis, vibrational spectroscopy (Raman and infrared) and single crystal X-ray diffraction analysis. Compound 1 was obtained under solvothermal conditions and 2 by the diffusion method. Structure determination by single crystal X-ray diffraction analysis revealed that compound 1 presents two-dimensional polymeric nature due to the bridging coordination mode of both BPP ligand and croconate anion. In this case, the croconate anion acts in the unprecedented μ-1,2-bis(monodentate) coordination mode, forming interpenetrated grids of 6³ topology. On the other hand, compound 2 is a three-dimensional 4-connected uninodal net of (4²·8⁴) topology, due to the presence of the flexible BPP ligand that bridges two Cu(II) sites connecting perpendicular one-dimensional polymeric chains, formed by croconate anions coordinated to the metal centers in a bis-bidentate coordination mode.     

Hetero-metallic frameworks of [Pd(CN)4] and Cu(II) with triamines: A rare example of a tetracyanometallate bridged 2D coordination polymer

Four cyano bridged Cu(II)–Pd(II) heterometallic complexes, [Cu(dpt)Pd(CN)₄]_n (1), {[Cu₂(medpt)₂Pd(CN)₄](ClO₄)₂ · 3H₂O}_n (2), {[Cu₂(dien)₂Pd(CN)₄](ClO₄)₂ · 2CH₃OH}_n (3) and {[Cu₂(iPrdien)₂Pd(CN)₄](ClO₄)₂ · 2H₂O}_n (4) [dpt = 3,3′-iminobispropylamine; medpt = 3,3′-diamino-N-methyldipropylamine; dien = diethylenetriamine and iprdien = N′-isopropyldiethylenetriamine] have been synthesized and characterized by single crystal X-ray diffraction analysis, magnetic measurement and thermal study. Complexes 1, 2 and 3 are 1D coordination polymers, while 4 presents a 2D network. In 1, the cis-directed cyanide ligands of [Pd(CN)₄]²⁻ anions link two Cu(dpt) units to form a neutral coordination polymer, whereas in 2, 3 and 4, all the cyanide groups of [Pd(CN)₄]²⁻ take part in bonding with four adjacent Cu(II) ions, resulting in cationic coordination polymers counterbalanced by perchlorate anions. The structures are compared with those of analogous [Ni(CN)₄]²⁻ derivatives. The magnetic behavior shows antiferromagnetic interactions in all the complexes.     

Two new coordination polymers of Robson-type macrocycle bridged by perchlorate anions: Structure,electrochemistry and magnetism

Two new coordination polymers of Robson-type macrocycles, [Cu₂L¹(μ-ClO₄)₂]_∞ (1) and [Cu₂L²(μ-ClO₄)₂]_∞ (2) (where H₂L¹and H₂L² are the [2+2] condensation products of 2,6-diformyl-4-flurophenol with 1,3-diaminopropane and 2-hydroxy-1,3-diaminopropane, respectively), have been synthesized and characterized. The intriguing feature is that intermolecular perchlorato bridges occur between adjacent copper(II) centers. The cyclic voltammograms of the complexes show that each complex undergoes two pseudo-reversible processes with the half wave potentials, −0.361 V and −0.729 V for 1, and −0.372 V and −0.744 V for 2, respectively. Magnetic susceptibility was measured for 1 and 2 over a temperature range of 2–300 K. The optimized magnetic data were J = −359.6 cm⁻¹, j′ = −30 cm⁻¹ and R = 6.8 × 10⁻⁸ for 1 and J = −411 cm⁻¹, j′ = −26 cm⁻¹ and R = 2.4 × 10⁻⁷ for 2, respectively. The data reveal antiferromagnetic couplings between the copper(II) ions of intra- and intermolecular units.     

The supramolecular chemistry of metal complexes with heavily substituted imidazoles as ligands: Cobalt(II) and zinc(II) complexes of 1-methyl-4,5-diphenylimidazole

An investigation of the M^II/X⁻/L [M^II = Co, Ni, Cu, Zn; X⁻ = Cl⁻, Br⁻, I⁻, NCS⁻, NO₃⁻, N₃⁻, CH₃COO⁻; L = 1-methyl-4,5-diphenylimidazole] general reaction system towards the detailed study of the intermolecular interactions utilized for controlling the supramolecular organization and the structural consequences on the structures produced has been initiated. Three representative complexes with the formulae [Co(NO₃)₂(L)₂] (1), [Zn(NO₃)₂(L)₂] (2) and [Co(NCS)₂(L)₂]·EtOH (3·EtOH) have been synthesized and characterized by spectroscopic methods and single-crystal X-ray analysis. Compounds 1 and 2 are isomorphous (tetragonal, I4₁cd) with their metal ions in a severely distorted octahedral Co/ZnN₂O₄ environment, while 3·EtOH crystallizes in P2₁/c with a tetrahedral CoN₄ coordination. The structural analysis of 1, 2 and 3·EtOH reveals a common mode of packing among neighbouring ligands (expressed through intramolecular π–π interactions between the 4,5-diphenylimidazole moieties), enhancing thus the rigidity and stability of the complexes. The bent coordination of the two isothiocyanates in 3 [Co–NCS angles of 173.8(2) and 160.8(2)°] seems to be caused by intermolecular hydrogen bonding and crystal packing effects.     

[Cu(men)2(BF4)2] (men = N-methyl-1,2-diaminoethane): Preparation, crystal structure, spectroscopic and magnetic properties

Single crystals of [Cu(men)₂(BF₄)₂] (men = N-methyl-1,2-diaminoethane) (1) were isolated from an aqueous-ethanolic system Cu²⁺-men-BF₄⁻. The crystal structure of 1 consists of [Cu(men)₂(BF₄)₂] molecules. Copper ion exhibits usual distorted octahedral coordination; there are two coordinated men ligands in the equatorial plane with Cu-N bonds of 2.0451(12) and 2.0035(12) Å, while the axial positions are occupied by fluorine atoms from BF₄⁻ anions with Cu-F bond of 2.5091(11) Å. The packing of the [Cu(men)₂(BF₄)₂] molecules is governed by N-H?F type hydrogen bonds. The measured ESR spectrum corroborated the presence of Jahn-Teller anisotropy of Cu(II) with g_|| = 2.20 and g_⊥ = 2.06. The magnetic studies in the temperature range 300-2 K reveal that 1 follows the Curie-Weiss law with parameters g = 2.1612(1) and θ = −0.233(1) K suggesting the presence of weak antiferomagnetic interactions.     

Syntheses and crystal structures of straight or zigzag one-dimensional coordination polymers based on Cu(II) square pyramidal or Cu(I) tetrahedral coordination environments

Two coordination polymers containing copper ions, [Cu(SO₄)(pyz)(H₂O)]_n (1) and [Cu₂(SO₄)(pyz)₂(H₂O)₂]_n (2) (pyz = pyrazine), have been synthesized and characterized by single-crystal X-ray analyses. Compound 1 was synthesized by the reaction of Cu(SO₄) · 5H₂O with pyz (ratio = 1:2) in H₂O at room temperature. The structure of 1 consists of linear chains of [Cu(pyz)(H₂O)]²⁺, with coordinated sulfate ions bridging the chains. Compound 2 was obtained as dark red blocks from the reaction of Cu(SO₄) · 5H₂O and pyz (ratio = 1:2) in H₂O, after heating to 180 °C in a Teflon autoclave for 48 h. The structure of 2 consists of zigzag chains of [Cu(pyz)(H₂O)]⁺ with sulfate ions. Only the difference in the synthesis temperature, room temperature or 180 °C, determines whether Cu(II) or Cu(I) coordination polymers are formed, with the reduction of Cu(II) to Cu(I) being explained by the Gillard mechanism.     

First and second coordination spheres in divalent metal compounds containing pyridine and 4,6-dimethyl-1,2,3-triazolo[4,5-d]pyrimidin-5,7-dione

The interaction in aqueous media of 4,6-dimethyl-1,2,3-triazolo[4,5-d]pyrimidin-5,7-dione (1,3-dimethyl-8-azaxanthine, Hdmax) with salts of divalent Mn, Co, Ni, Cu, Zn and Cd in the presence of an excess of pyridine (py) leads to the formation of crystalline solids, the structures of which have been solved by single crystal X-ray diffraction. The solids containing Mn, Co, Zn and Cd are isostructural, presenting a formulation trans-[M(H₂O)₄(py)₂](dmax)₂, with the heterocycle in the anionic form and not directly linked to the metal atom. The H-bond network of these complexes include a tape superstructure topologically identical to that present in the previously reported hexa-aqua salts of the dmax⁻ anion, which may be regarded as a case of molecular recognition between dmax⁻ and the square planar [M(H₂O)₄] subunit. On the other hand, for Ni and Cu the triazolopyrimidine ligand is directly coordinated to the metal through the external imidazole nitrogen atom (N2) generating the compounds [M(dmax)₂(H₂O)₂(py)₂] · 2H₂O, which display a less tight H-bonding network.     

A new [Ni4] distorted cubane assembly on four solvent derived μ3-OMe corners: Solvent dependent formation and cleavage of exogenous bridges

A new Ni₄ distorted cubane complex [Ni₄(μ₃-OMe)₄Q₄(MeOH)₄] (1) (where Q⁻ is the anion of 8-quinolinol) is obtained from the reaction of NaQ with Ni(OAc)₂ · 4H₂O in refluxing MeOH via solvent derived μ₃-OMe assisted self-assembly of four nickel(II) centres. The periphery of [Ni₄(OMe)₄] cubane is covered by four Q⁻ and four MeOH molecules. This methanol specific reaction is not supported in solvent glycinol (Hgl; NH₂(CH₂)₂OH), an amine substituted ethanol, producing monomeric [NiQ₂(Hgl)₂] · 2H₂O (2 · 2H₂O) instead and is able to cleave 1 to yield 2 · 2H₂O. The cryomagnetic susceptibility data of powdered 1 can be modeled by a two J equation yielding J₁ = −1.8(1) cm⁻¹, J₂ = 3.9(1) cm⁻¹ and g = 2.24.     

The first heterometallic Cu(II)/Cr(III) complex with an open-chain Schiff-base ligand self-assembled from copper powder,Reineckes salt,ethylendiamine and acetone

A novel supramolecular assembly [{Cu(enac)}₂Cr(NCS)₄(NH₃)₂][Cr(NCS)₄(NH₃)₂]₃ · 4(CH₃)₂CO (enac = 4,6,6-trimethyl-3,7-diazanon-3-ene-1,9-diamine), the first example of a Cu/Cr heterometallic compound containing a Schiff-base ligand such as enac, and an anion of Reineckes salt, Cr(NCS)₄(NH₃)₂⁻, as a building block, was obtained by the self-assembly reaction of copper powder and Reineckes salt in an acetone/methanol (1:4) solution of ethylenediamine in the open air. An X-ray study shows that the complex includes a trinuclear Cu₂Cr cation, constructed from two Cu(enac)²⁺ moieties and a trans-[Cr(NCS)₄(NH₃)₂]⁻ block as a two-linking bridging ligand. The metal–metal separations within the cation are Cu?Cr = 6.393(31) Å and Cu?Cu = 12.786(63) Å. The supramolecular architecture of the complex involves two types of H-bonded chains, the first chain is generated by trinuclear cations [{Cu(enac)}₂Cr(NCS)₄(NH₃)₂]²⁺, [Cr(NCS)₄(NH₃)₂]⁻ anions and (CH₃)₂CO molecules, while the second by crystallographically different anions of Reineckes salt and (CH₃)₂CO. Variable-temperature (1.8–300 K) magnetic susceptibilities show a slight change of the μ_B value at low temperature, indicative of weak antiferromagnetic interactions (J_CuCr = −0.9 cm⁻¹) between the paramagnetic centers.     

Complexes derived from the general copper(II)/maleamic acid/N,N′,N′′-chelate reaction systems: Synthetic,reactivity, structural and spectroscopic studies

The synthetic investigation of the Cu^II/maleamate(−1) ion (HL⁻)/N,N′,N′′-chelate general reaction system has allowed access to compounds [Cu₂(HL)₂(bppy)₂](ClO₄)₂·H₂O (1·H₂O), [Cu(HL)(bppy)(ClO₄)] (2) and [Cu(HL)(terpy)(H₂O)](ClO₄) (4) (bppy = 2,6-bis(pyrazol-1-yl)pyridine, terpy = 2,2′;6′,2′′-terpyridine). In the absence of externally added hydroxides, compound [Cu₂(L′)₂(bppy)₂](ClO₄)₂ (3) was obtained from MeOH solutions; L′⁻ is the monomethyl maleate(−1) ligand which is formed in situ via the Cu^II-assisted HL⁻ → L′⁻ transformation. In the case of tptz-containing (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine) reaction systems, the Cu^II-assisted hydrolysis of tptz to pyridine-2-carboxamide (L1) afforded complex [Cu(L1)₂(NO₃)₂] (5). The crystal structures of 1–5 are stabilized by intermolecular hydrogen bonding and π–π stacking interactions. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the ligands.     

Solid phase extraction of zinc(II) using a PVC-based polymer inclusion membrane with di(2-ethylhexyl)phosphoric acid (D2EHPA) as the carrier

A polymer inclusion membrane (PIM) is reported consisting of 45% (m/m) di(2-ethylhexyl)phosphoric acid (D2EHPA) immobilized in poly(vinyl chloride) (PVC) for use as a solid phase absorbent for selectively extracting Zn(II) from aqueous solutions in the presence of Cd(II), Co(II), Cu(II), Ni(II) and Fe(II). Interference from Fe(III) in the sample is eliminated by precipitation with orthophosphate prior to the extraction of Zn(II). Studies using a dual compartment transport cell have shown that the Zn(II) flux (2.58 × 10⁻⁶ mol m⁻² s⁻¹) is comparable to that observed for supported liquid membranes. The stoichiometry of the extracted complex is shown to be ZnR₂·HR, where R is the D2EHPA anion.     

Zinc(II) complexes of 1,3-bis(2-pyridylmethylthio)propane: Anion dependency, crystal structure and DNA binding study

Zinc(II) complexes of the formula [Zn(L)(X)₂] (where X = Cl⁻, N₃⁻, NCO⁻ and SCN⁻ (1a-d, respectively)) and {[Zn(L)(ClO₄)(H₂O)](ClO₄)}_n (2), were isolated in the pure form on the reaction of 1,3-bis(2-pyridylmethylthio)propane (L) with different zinc(II) salts. All the complexes were characterized by physicochemical and spectroscopic tools. The X-ray crystallographic analyses of the complexes 1d and 2 showed that the former is mononuclear while complex 2 is a 1D coordination polymer, {[Zn(L)(ClO₄)(H₂O)](ClO₄)}_n, due to a different coordination mode of the tetradentate ligand L. The zinc(II) ions present an octahedral coordination geometry in both compounds, which is more distorted in the mononuclear complex 1d. The study indicates that the counter anion of the zinc(II) salt used as reactant leads to a different type of complex when isolated as a crystalline material. A spectroscopic study of the interaction of complex, 2 with calf thymus-DNA (CT-DNA) in Tris-HCl buffer showed a significant non-intercalative interaction with a binding constant (K_b) of 4.7 × 10⁴ M⁻¹, and the linear Stern-Volmer quenching constant (K_sv) and the binding sites (n) were found to be 1.3 × 10³ and 0.92 respectively, calculated from ethidium bromide (EB) fluorescence displacement experiments.     

Homoleptic [M(XeF2)6] cations of copper(II) and zinc(II)—Syntheses and crystal structures of [M(XeF2)6](SbF6)2 (M = Cu, Zn)

[Cu(XeF₂)₆](SbF₆)₂ crystallizes in the rhombohedral symmetry with a = 1003.6(2) pm, c = 2246.5(12) pm at 200 K and Z = 3, space group (No. 148). [Zn(XeF₂)₆](SbF₆)₂ is isostructural to [Cu(XeF₂)₆](SbF₆)₂ with a = 1007(2) pm and c = 2243(6) pm. The structures are characterized by isolated homoleptic [M(XeF₂)₆]²⁺ (M = Cu, Zn) cations and of [SbF₆]⁻ octahedra.Reactions of M(SbF₆)₂ (M = Cu, Zn) with XeF₂ in anhydrous hydrogen fluoride (aHF) and reactions of MF₂ with Xe₂F₃SbF₆ in aHF always yield a mixture of [M(XeF₂)₆](SbF₆)₂, Xe₂F₃SbF₆ and MF₂.     

Structure and magnetism of Co(II) complexes with bidentate heterocyclic ligand Hsalbim derived from benzimidazole

Two mononuclear Co(II) complexes based upon 2-(1H-benzimidazol-2-yl)phenol, abbreviation Hsalbim ligand, have been prepared and studied. The structure of Hsalbim and [Co(salbim)₂] have been confirmed by X-ray structure analysis. The second cobalt(II) complex matches the formula [Co(salbim)₂]·(Hsalbim)·MeOH assuming a co-crystallization of one neutral ligand. The electronic spectra are consistent with the tetrahedral pattern. Magnetic susceptibility measurements down to T = 2 K along with the magnetization data until B = 7 T show that the Co(II) complexes are high-spin with a considerable zero-field splitting of the ⁴B₁(D_2d) term: D/hc = 67 and 55 cm⁻¹, respectively.     

Structural and X-ray powder diffraction studies of nano-structured lead(II) coordination polymer with η Pb?C interactions

A new nano-sized Pb(II) one-dimensional coordination polymer with η² Pb-C interactions, [Pb₂(μ₃-ba)₂(μ₂-ba)₂]_n (1) [ba⁻ = benzylacetylacetonate] has been synthesized and characterized by SEM, X-ray powder diffraction, IR spectroscopy and elemental analyses. Single-crystal X-ray diffraction shows the coordination number of Pb(II) ions is seven and the lead atoms have hemidirected coordination sphere containing involving Pb?C interactions, C₂O₇Pb. PbO nanoparticles were obtained by calcinations of the nano-sized compound 1 at 600 °C.