The synthesis, structural characterization, magnetochemistry and Mössbauer spectroscopy of [Fe3LnO2(CCl3COO)8H2O(THF)3] (Ln = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Lu and Y)

The new tetranuclear complexes [Fe₃Ln(μ₃-O)₂(CCl₃COO)₈(H₂O)(THF)₃]·THF (Ln = Ce^III (1), Pr^III (2), Nd^III (3)) and [Fe₃Ln(μ₃-O)₂(CCl₃COO)₈(H₂O)(THF)₃]·THF·C₇H₁₆ (Ln = Sm^III (4), Eu^III (5), Gd^III (6), Tb^III (7), Dy^III (8), Ho^III (9), Lu^III (10) and Y^III (11)) have been prepared. All compounds were prepared by the reaction between [Fe₂BaO(CCl₃COO)₆(THF)₆] and the corresponding Ln^III nitrate salt. The crystal structures of 1–4, 8 and 9 have been determined; these isostructural molecules have a non-planar {Fe₃Ln(μ₃-O)₂} “butterfly” core. Magnetic susceptibility measurements show dominant intramolecular antiferromagnetic exchange interactions for all the complexes. ⁵⁷Fe Mössbauer spectroscopy shows three different environments for the Fe^III metal ions, all in their high-spin state S = 5/2 (confirming that no electron transfer from Ce^III to Fe^III occurs in 1). At the time scale of the Mössbauer spectroscopy (about 10⁻⁷ s), evidence of magnetization blocking, i.e. slow relaxation of the magnetization, is observed below 3 K for 7, which was confirmed by ac susceptibility measurements.     

A series of novel 1D coordination polymers constructed from metal–quinolone complex fragments linked by aromatic dicarboxylate ligands

Self-assembly of quinolones with metal salts in the presence of aromatic dicarboxylate ligands affords a series of novel 1D metal–quinolone complexes, namely [Mn(Hppa)(oba)]·3H₂O (1), [Co(Hppa)(oba)]·3.25H₂O (2), [Zn(Hppa)(sdba)]·1.5H₂O (3), [Mn(Hcf)(bpda)(H₂O)]·2H₂O (4), [Mn(Hppa)₂(bpdc)] (5) and [Mn(Hlome)₂(bpdc)]·4H₂O (6) (Hppa = Pipemidic acid, Hcf = ciprofloxacin, Hlome = lomefloxacin). The structures of compounds 1–3 consist of novel polymeric chains spanning two different directions, which display an intriguing 1D → 3D inclined polycatenation of supramolecular ladders. Compound 4 exhibits a chain compound formed from the interconnection of [Mn₂(Hcf)₂(μ-CO₂)₂] dimers with bpda ligands. Compounds 5 and 6 are similar chain compounds constructed from [Mn(Hppa)₂] (or [Mn(Hlome)₂]) fragments linked by bpdc ligands. The magnetic properties of 4 have been studied, which indicate the existence of antiferromagnetic interactions. Furthermore, the luminescent properties of compound 3 are discussed.     

pH-Directed assembly of four polyoxometalate-based supramolecular hybrids by using tritopic bridging ligand 1, 3, 5-tris-(1-imidazolyl)-benzene: Structures and electrocatalytic properties

Four new inorganic-organic supramolecular compounds, namely, (H₂tib)₂[GeW₁₂O₄₀] (1), [Mn(Htib)₄][HGeW₁₂O₄₀]₂·4H₂O (2), [Mn(tib)]₂(H₂O)₆[GeW₁₂O₄₀]·4H₂O (3) and [Mn(tib)]₂(H₂O)₆[GeW₁₂O₄₀]·2H₂O (4) (tib = 1, 3, 5-tris-(1-imidazolyl)-benzene), have been synthesized through the hydrothermal reaction of [GeW₁₂O₄₀]^4- anions, Mn^II cations and tib ligands under different pH conditions. Compounds 1 and 2 were prepared at lower pH (pH ≈ 2.0 for 1 and 3.2 for 2). Compound 1 exhibits a simple monomer structure. In 2, the Mn cation is coordinated with four tib ligands and two [GeW₁₂ O₄₀]^4- anions to form a dimer, in which each of [GeW₁₂ O₄₀]^4- anion connects with one Mn cation. Compounds 3 and 4 were prepared at higher pH (pH ≈ 4.2 for 3 and 4.9 for 4), and compounds 3 and 4 display a one-dimensional (1D) chain and a (4, 4)-connected 2D wave-like layer, respectively, and in compound 3, each of GeW₁₂ cluster connects two Mn atoms, however, compound 4: each of GeW₁₂ cluster connects four Mn atoms. The isolation of these four compounds is very informative for systematically understanding the effect of the pH on assembly of polyoxometalate-based hybrids. Also, the electrocatalytic properties of 1–4-CPEs towards nitrite have also been investigated.     

Synthesis,characterization and crystal structure of triphenylphosphine copper(I) methylpyruvate thiosemicarbazones

This paper reports the synthesis of a series of methylpyruvate thiosemicarbazone derivatives containing, on the terminal nitrogen, substituents of different nature and size and namely, ethyl, phenyl and methylphenyl. These ligands were reacted with bis(triphenylphosphine)copper(I) nitrate and acetate to produce the respective complexes: [Cu(PPh₃)₂(Et-Hmpt)]₂(NO₃)₂ (1), [Cu(PPh₃)₂(Ph-Hmpt)]NO₃ (2), [Cu(PPh₃)₂(MePh-Hmpt)]NO₃ (3), [Cu₂(O₂CCH₃)(Et-pt)(PPh₃)₂] · H₂O (4), [Cu(Ph-mpt)(PPh₃)] (5) and [Cu₂(MePh-mpt)₂(PPh₃)₂] (6). All of them were characterized by elemental analysis, IR, ¹H NMR, EPR spectroscopy and, for compounds 1, 2, 4, and 6, by X-ray crystallography. The characterization revealed that the coordinating behaviour of the ligands is influenced by a series of factors, predominant among which is the hard soft nature of the atoms involved in the interactions with the metal centre. The complexes obtained from the nitrate copper(I) salt are formed by cationic molecules with a nitrate as a counterion, while those derived from the acetate salt present deprotonated ligands and a few unexpected features. In particular, one of the compounds (4) is a mixed valence dinuclear complex with an acetate oxygen and the thiosemicarbazone sulfur acting as bridging between the two Cu(I) and Cu(II) ions. Another one (6) presents instead a Cu(I)–Cu(I) sulfur bridged binuclear cluster.     

Isomerism in tetrahedral rhenium cluster complexes [Re4Q4(PMe2Ph)4X8]·nCH2Cl2 (Q = Se, X = Br; Q = Te, X = Cl, Br)

Three new tetrahedral rhenium cluster compounds [Re₄Se₄(PMe₂Ph)₄Br₈]·1.5CH₂Cl₂ (1), [Re₄Te₄(PMe₂Ph)₄Br₈]·CH₂Cl₂ (2), and [Re₄Te₄(PMe₂Ph)₄Cl₈]·CH₂Cl₂ (3) have been synthesized by the reaction of the corresponding precursor chalcohalide complexes [Re₄Q₄(TeX₂)₄X₈] (X = Br, Q = Se (for 1), Te (for 2); X = Cl, Q = Te (for 3)) with dimethylphenylphosphine in CH₂Cl₂. All compounds have been characterized by X-ray single-crystal diffraction and elemental analyses, IR and ³¹P NMR spectroscopy. ³¹P NMR spectroscopy indicates the formation of isomers in solution, confirmed by single-crystal X-ray analysis.     

Syntheses and characterizations of five coordination polymers constructed by 3,5-bis(pyridin-3-ylmethoxy)benzoic acid ligand

Five coordination polymers, namely [Cd(L3)₂]·H₂O (1), [Zn(L3)₂] (2), [Co(L3)₂] (3), [Ni(L3)₂] (4) and [Cu₂(L3)₂]·3H₂O (5), where L3 = 3,5-bis(pyridin-3-ylmethoxy)benzoic acid, have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compound 1 is a binodal (3,4)-connected net with (6³)(6⁶) topology. Compounds 2–4 are isostructural and described by the uninodal (4,4)-connected net with (4⁴ · 6²) Schläfli symbol. The structure of 5 is a 2D binodal (6,3) net. In addition, the luminescent properties of compounds 1 and 2 have been studied in the solid state at room temperature.     

Structural and magnetic studies of tetranuclear heterometallic M/Cr (M = Co,Mn) complexes self-assembled from zerovalent cobalt or manganese,Reineckes salt and diethanolamine

Four novel heterometallic complexes [Co₂Cr₂(NCS)₄(HDea)₂(Dea)₂]·4dmf (1), [Co₂Cr₂(NCS)₄(HDea)₂(Dea)₂]·4dmso (2), [Mn₂Cr₂(NCS)₄(HDea)₂(Dea)₂(dmf)₂]·2dmf (3) and [Mn₂Cr₂(NCS)₄(HDea)₂(Dea)₂(dmso)₂]·4dmso (4) have been prepared using zerovalent cobalt (1, 2) or manganese (3, 4), Reineckes salt, ammonium thiocyanate and a non-aqueous solution of diethanolamine (H₂Dea) in air. The single X-ray analysis reveals that all compounds have similar centrosymmetric crystal structures based on a tetranuclear {M₂Cr₂(μ₃-O)₂(μ-O)₄} (M = Co, Mn) core. Variable-temperature magnetic susceptibility measurements of 1, 2 and 4 show antiferromagnetic coupling between the magnetic centers, while 3 exhibits a ferromagnetic behavior.     

An investigation of the positional isomeric effect of terpyridine derivatives: Self-assembly of novel cadmium coordination architectures driven by N-donor covalence and π⋯π non-covalent interactions

Four cadmium compounds based on two pyridyl substituted terpyridine isomers, namely {[Cd₃(L1)₂(SCN)₆](THF)₂}_n (1), [Cd₂(L1)(CH₃OH)Cl₄]_n (2), [Cd₂(L2)₂(N₃)₄] (3) and [Cd₂(L2)₂(SCN)₄] (4) (L1 = 4′-(3-pyridyl)-2,2′:6′,2″-terpyridine, L2 = 4′-(2-pyridyl)-2,2′:6′,2″-terpyridine) have been synthesized and characterized by IR, elemental analyses, and luminescent spectroscopy with the purpose of investigating the influence of isomeric effect on network assembly. In compounds 1 and 2, L1 as a mono-tridentate bridging ligand links Cd^II atoms into 1D grid-like and 2D wave-like polymers. In contrast, in compounds 3 and 4, L2 as a chelating ligand forms Cd^II dimeric structures. The different coordination behaviors and the positional isomer effect were discussed under the same reaction conditions. In addition, three kind of π?π interactions in the four compounds were summarized, two of which could not be observed on tpy-based complexes.     

Metal coordination architectures of triazole-based ligands: Effect of the backbone of bridging ligands on the construction of polymers

In our efforts to investigate the influence of the backbone of different triazole-based bridging ligands on the structure of their metal complexes, four new coordination polymers, {[Cu(L¹)₂(H₂O)₂]Cl₂}_n (1), [Cu(L²)₂Cl₂]_n (2), [Co(L²)₂(SCN)₂]_n (3), and [Cu(L³)₂(NO₃)₂]_n (4), (L¹ = 1,2-bis(triazol-1-ylmethyl)benzene, L² = 1,3-bis(triazol-1-ylmethyl)benzene, L³ = 1,4-bis(triazol-1-ylmethyl)benzene), have been synthesized. All the complexes have been structurally characterized by IR, elemental analysis and single-crystal X-ray diffraction. Structural analyses show that 1 and 4 possess 2D coordination networks with (4,4) topology, and 1 shows a diagonal–diagonal inclined interpenetration. 2 and 3 are isostructural and feature 1D double chain, which further connected by C–H···Cl or π···π weak interactions to form 2D supramolecular frameworks. The results show that the structures of ligands (with different non-coordination backbone spacers) play important roles in the formation of such coordination architectures. Furthermore, EPR (Electron Paramagnetic Resonance) spectra of Cu^II complexes (1, 2, and 4) have been investigated in the solid state at room temperature.     

Synthesis,crystal structures,and luminescent properties of three cluster-based heterometallic and monometallic compounds

Two heterometallic cluster compounds and one monometallic cluster compound, namely [Ni₉Co₆(PMIDA)₆(BTC)₂(H₂O)₁₂]·6H₂O (1), [Co₁₃Zn₂(PMIDA)₆(H₂O)₁₈]·6NO₃·15H₂O (2), and [Fe₁₅(PMIDA)₆(BTC)₂(H₂O)₂₂]·38H₂O (3), have been obtained under hydrothermal conditions using N-(phosphonomethyl)imino-diacetic acid (H₄PMIDA) and 1,3,5-benzenetricarboxylate acid (H₃BTC) as ligands, and structurally characterized by X-ray crystallography. Compound 1 exhibits a 3D open framework constructed from [Ni₉Co₆(PMIDA)₆(H₂O)₁₂]⁶⁺ heteronuclear clusters and BTC^3? ligands. Compounds 2 and 3 are both zero-dimensional polynuclear clusters, further extended into 3D supramolecular structures via hydrogen-bonding interactions. However, there are some differences in their crystal structures; compound 2 features an isolated spherical heteronuclear cation cluster based on PMIDA^4? ligands, such that the NO₃ ^? anions only balance the charge, whereas compound 3 is characterized as a neutral monometallic cluster incorporating two different types of organic acid ligands, namely PMIDA^4? and BTC^3?, and the two BTC^3? ligands exhibit regular distribution in each cluster. The luminescence properties of all three compounds have been investigated at room temperature.     

An experimental and theoretical investigation on hypervalent organoselenium(II) halides: Case study of [2-(Et2NCH2)C6H4]SeX (X = Cl,Br, I)

Cleavage of the Se–Se bond in [2-(Et₂NCH₂)C₆H₄]₂Se₂ (1) with SO₂Cl₂ (1:1 molar ratio) yielded the organoselenium(II) chloride [2-(Et₂NCH₂)C₆H₄]SeCl (2). Treatment of 2 with excess of KX yielded the organoselenium(II) halides [2-(Et₂NCH₂)C₆H₄]SeX [X = Br (3), I (4)]. The new compounds 2–4 were characterized by solution NMR spectroscopy (¹H, ¹³C, ⁷⁷Se, 2D experiments). The solid-state molecular structures of 2, 2·HCl and 3 were established by single crystal X-ray diffraction. Distorted T-shaped coordination geometries of type (C,N)SeX (X = Cl, Br) and CSeCl₂ were found for the neutral halides 2 and 3, and the zwitterionic species [2-{Et₂N⁺(H)CH₂}C₆H₄]SeCl₂￣ (2·HCl), respectively. DFT calculations were performed on 2–4 and the related tellurium compounds [2-(Et₂NCH₂)C₆H₄]TeX [X = Cl (5), Br (6) and I (7)] in order to elucidate the bond nature and FT-Raman features of this class of organochalcogen(II) derivatives.     

Synthesis,characterization and X-ray crystal structure determination of cyclopalladated [Csp2,N,N′]−, zwitterionic and chelated compounds in the reaction of 3,5-diphenyl-N-alkylaminopyrazole derived ligands with Pd(II)

The synthesis of two N-alkylaminopyrazole ligands, 1-[2-(diethylamino)ethyl]-3,5-diphenylpyrazole (L1) and 1-[2-(dioctylamino)ethyl]-3,5-diphenylpyrazole (L2), is reported. These ligands present, a priori, one pyrazole nitrogen and one amine nitrogen as potential donor atoms. However, in the reaction of the ligands (L1 and L2) with [PdCl₂(CH₃CN)₂] one of the C_phenyl atoms can also behave as a donor atom. As a result, we have obtained the formation of three different compounds for each one of the ligands: chelated ([PdCl₂(L)] L = L1 (1a), L2 (2a)), zwitterionic ([PdCl₃(LH)] LH = LH1 (1b), LH2 (2b)), and cyclopalladated compounds ([PdCl(LC)] (LC = LC1 (1c), LC2 (2c)). The solid-state structures for 1a, 1b and 1c were determined by single crystal X-ray diffraction methods. The potentially [C,N,N′]^? ligand is coordinated through the N_pz and the N_amino to the metal atom for 1a, through the N_pz for 1b, and through the N_pz, the N_amino and a C_phenyl for 1c.     

Crystal structure and optical properties of new 0D-hybrid hydroxyfluorotitanates

New 0D hybrid organic–inorganic hydroxyfluorotitanates result from the microwave assisted reactions in autoclaves of TiF₄ with organic amines (3-5 diamino-1,2,4,triazol (guaz), ethylenediamine (en) and diethylenetriamine (dien)) and concentrated aqueous HF in ethanol at 190 °C for 1 h. Four compounds, [Hguaz]₂·(TiF_4.9(OH)_1.1) (I), [H₂guaz]·(TiF_4.8(OH)_1.2) (II), [H₂en]·(TiF_4.3(OH)_1.7) (III) and [H₂dien]·(Ti(F,OH)₆)·2H₂O (IV) are prepared and characterized. All structures are built up from isolated (Ti(F,OH)₆)²⁻ anions interacting with mono- or di-protonated amines which local symmetry dictates the long range stacking of the Ti(F,OH)₆ octahedra. Insertion of crystallized water molecules is only observed for IV. The experimental optical gaps of I, II and III have been measured at about 3.4 eV and compare well with the theoretical values estimated from the examination of density of state diagrams. The optical thresholds are mainly due to O(2p) → Ti(3d) electronic transitions, the F(2p) → Ti(3d) charge transfers occurring at higher energy.     

Novel inorganic ionic compounds based on Re6 chalcocyanide cluster complexes: synthesis and crystal structures of [CuNH3(trien)]2[Re6S8(CN)6] · 7H2O, [CuNH3(trien)]2[Re6Se8(CN)6] and [CuNH3(trien)]2[Re6Te8(CN)6] · H2O

Three new octahedral rhenium chalcocyanide cluster compounds [CuNH₃(trien)]₂[Re₆S₈(CN)₆] · 7H₂O (1), [CuNH₃(trien)]₂[Re₆Se₈(CN)₆] (2) and [CuNH₃(trien)]₂[Re₆Te₈(CN)₆] · H₂O (3) exhibiting ionic structures have been obtained by the diffusion of an ammonia solution of KCs₃[Re₆S₈(CN)₆] (for 1), K₄[Re₆Se₈(CN)₆] · 3.5H₂O (for 2) or Cs₄[Re₆Te₈(CN)₆] · 2H₂O (for 3) into a glycerol solution of CuCl₂ · 2H₂O in the presence of trien (trien=triethylenetetramine). The compounds have been characterized by single-crystal X-ray diffraction. All three compounds contain a cationic complex [CuNH₃(trien)]²⁺ which was not described previously.     

Metal coordination architectures of N-propionyl-1-hydroxy-2-naphthoylhydrazide: From metalladiazamacrocycles to trinuclear complexes

Two metalladiazamacrocycles, 24-membered octanuclear [Mn₈(pnhz)₈(DMF)₅(MeOH)₃]2DMF 3.5MeOH (1) and 18‐membered hexanuclear [Fe₆(pnhz)₆(DMF)₆] (2), and two linear trinuclear complexes, [Cu₃(pnhz)₂(Py)₆] 2Py (3) and [Ni₃(pnhz)₂(Py)₄] (4), have been synthesized based on a trianionic pentadentate bridging ligand N-propionyl-1-hydroxy-2-naphthoylhydrazide (H₃pnhz). The complexes are characterized by elemental analysis, IR, UV-vis spectroscopy and single-crystal X-ray diffraction. The nature of metal ions and steric effect of N-propionyl-1-hydroxy-2-naphthoylhydrazide ligand play key roles in the formation of complexes with different nuclearity. Complexes 1, 2 and 3 exhibit antiferromagnetic coupling interactions between the metal centers.     

Synthesis and properties of iron (II) quinoline-2-carboxylates,crystal structure of trans-diaquabis(quinoline-2-carboxylato)iron (II) bis(dichloromethane) solvate

Two mononuclear iron complexes with the quinoline-2-carboxylate ion (quin-2-c ion) have been obtained by the reaction of iron powder with quinoline-2-carboxylic acid in dichloromethane. The compounds [Fe(quin-2-c)₂] (1), [Fe(quin-2-c)₂(H₂O)₂] · 2CH₂Cl₂ (2) and [Fe(quin-2-c)₂(H₂O)₂] · 2EtOH · 2H₂O (3) have been investigated by IR and UV–Vis spectroscopy, magnetic susceptibility and field-dependent magnetization measurements. The structure of 2 has been characterised by X-ray diffraction. The 2D bilayered frameworks of 2 and 3 are constructed by extensive hydrogen bonding interactions between water and the organic ligand coordinated to iron (II). The magnetic properties of 2 and 3 were interpreted on the basis of a spin Hamiltonian that included axial and rhombic crystal field components. The weak antiferromagnetic (2) and ferromagnetic (3) interactions are evident in the low temperature data and possibly occur via strong hydrogen bonds.     

Synthesis and structure of new aryltellurenyl halides derived from (dmpTe)2 (dmp = 2,6-dimethoxyphenyl)

[RTeTeR] (R = dmp = 2,6-dimethoxyphenyl) (1) reacts with bromine to give [RTeTe(Br)₂R] (2) and [RTeBr₃] (3), and with SOCl₂ to yield [RTeTe(Cl)₂R] (5) and [RTeCl₃] (6). The recrystallization of compound 3 in acetone produces [RTeBr₂(CH₂-C(O)-CH₃)] (4). The hydrolysis of 2 in aqueous ammonia and methanol containing media affords the methoxy/oxo-derivative [RTe(μ-O)(OCH₃)]₂ (7). All the title compounds were obtained with good yields, and strong Te?O_(methoxy), as well as Te?X (X = Br, Cl) secondary interactions, support the distorted octahedral configurations shown mostly in the polymeric compounds 3, 4, 5 and 6. Complexes 2 and 5 close the series of compounds with the structure [RTeTe(X)₂R] (X = Cl, Br, I), started earlier with [RTeTe(I)₂R].     

Synthesis,characterization, and thermal behavior of palladium(II) complexes containing 4-iodopyrazole

The mononuclear pyrazolyl complexes [PdCl₂(HIPz)₂] (1), [PdBr₂(HIPz)₂] (2), [PdI₂(HIPz)₂] (3), [Pd(SCN)₂(HIPz)₂] (4), and [Pd(NHCOIPz)₂] (5) have been prepared. Compound 1 was obtained from the displacement of acetonitrile from [PdCl₂(CH₃CN)₂] precursor by the 4-iodopyrazole (HIPz) ligand, whereas 2–5 were synthesized by substitution of the chlorido in 1 by the respective anionic group. The compounds were characterized by elemental analysis, infrared spectroscopy, and ¹H NMR spectroscopy. The thermal behavior of 1–5 has been studied by TG and DTA. The thermal stability of [PdX₂(HIPz)₂] compounds varies according to the trends X = Cl^? < I^? ? SCN^?< Br^?. No stable intermediates were isolated during the thermal decompositions due to the overlap of the degradation processes. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.     

Mono- and di-nuclear complexes of thiosemicarbazones with copper(I): Synthesis,spectroscopy and structures

Reactions of copper(I) halides with a series of thiosemicarbazones, namely, benzaldehyde thiosemicarbazone (R¹R²CN–NH–C(S)–NH₂, R¹ = Ph, R² = H; Hbtsc), 2-benzoylpyridine thiosemicarbazone (R¹ = Ph, R² = py; Hbpytsc), and acetone thiosemicarbazone (R¹ = R² = Me; Hactsc), in the presence of PPh₃ has formed dimeric complexes, viz. sulfur bridged [Cu₂(μ-S-Hbtsc)₂Br₂(PPh₃)₂]·2H₂O (1), iodo-bridged [Cu₂(μ-I)₂(η¹-S-Hbtsc)₂(PPh₃)₂] (2), and heterobridged [Cu₂(μ₃-S,N³-Hactsc)(η¹-Br)(μ-Br)(PPh₃)₂] (3), as well as mononuclear complexes [CuX(η¹-S-Hbpytsc)(PPh₃)₂]·CH₃CN (X = Br, 4; Cl, 5). Complexes 1, 2, 4 and 5 involve thiosemicarbazone ligands in η¹-S bonding mode while in compound 3, ligand acts in N³, S-chelation-cum-S-bridging mode (μ₃-S,N³ mode). The intermolecular interactions such as, N²H?X, HN¹H?X (X = S, Br, Cl), CH?π interactions lead to 2D networks. All the complexes have been characterized with the help of elemental analyses, IR, ¹H, and ³¹P NMR spectroscopy, and single crystal X-ray crystallography. The role of a solvent in alteration of nuclearity and bonding modes of complexes has been highlighted.     

Platinum(IV) complexes with α,ω-bis(pyrazol-1-yl) alkanediyl and diethyl ether/thioether ligands. Crystal structures of dibromodimethyl[1,2-bis(pyrazol-1-yl)ethane]platinum(IV) and trimethyl-bis[2-(pyrazol-1-yl)ethyl]etherplatinum(IV) tetrafluoroborate

Reactions of the flexible α,ω-bis(pyrazol-1-yl) compounds 1,2-bis(pyrazol-1-yl)ethane (L1), 1,8-bis(pyrazol-1-yl)-n-octane (L2), bis[2-(pyrazol-1-yl)ethyl]ether (L3) and bis[2-(pyrazol-1-yl)ethyl]thioether (L4) with precursor organometallic platinum complexes ([(PtBr₂Me₂)_n], [(PtIMe₃)₄] and [(PtMe₂(cod)]/I₂) are described herein. The spectroscopic characterization of the platinum(IV) products of these reactions [PtBr₂Me₂{pz(CH₂)_mpz}], m = 2 (1) or 8 (2), [PtI₂Me₂{pz(CH₂)₂pz}] (3), [PtMe₃(pzCH₂CH₂OCH₂CH₂pz)][BF₄] (4) and [PtMe₃(pzCH₂CH₂SCH₂CH₂pz)][CF₃SO₃] (5), where ‘pz’ is pyrazol-1-yl, is discussed. Furthermore, solid state structures of 1, a complex with a seven-membered chelate ring, and 4, a complex bearing the neutral κ²N,N′,κO ligand bis[2-(pyrazol-1-yl)ethyl]ether (L3) are reported.