Complexes of copper(II) and cobalt(II) halides with 4-(3,5-dimethyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)-6-methyl-2-phenylpyrimidine: Synthesis,structures, and properties

Copper(II) and cobalt(II) complexes with 4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-methyl-2-phenylpyrimidine (L) of the general formula MLX₂ (M = Cu(II), X = Cl and Br; M = Co(II), X = Cl, Br, and I) were obtained. According to X-ray diffraction data, CuLBr₂ and CoLX₂ (X = Cl, Br, and I) are mononuclear molecular complexes. The ligand L is coordinated to the metal atom in a chelating bidentate fashion through the N atoms of the pyrimidine and pyrazole rings. The coordination polyhedron of the metal atom is extended to a distorted tetrahedron by two halide ions. In solution, CuLBr₂ undergoes slow transformation into CuL_(1?x)L′ _x Br₂ and the binuclear (X-ray diffraction data) Cu(I) complex [CuL_(1?x)L′ _x Br]₂ (L′ is 4-(4-bromo-3,5-dimethyl-1H-pyrazol-1-yl)-6-methyl-2-phenylpyrimidine). The complexes MLX₂ show weak antiferromagnetic interactions between the M²⁺ ions.     

Structure and luminescent properties of the cadmium(II) chloride complex with bis(benzotriazole-1-YL)methane

A procedure to synthesize a cadmium(II) chloride complex with bis(benzotriazole-1-yl)methane (L) of the composition [Cd₂L(H₂O)(C₂H₅OH)Cl₄] _n · 1.5nH₂O is developed. The compound was studied by single crystal and powder X-ray diffraction. According to the single crystal X-ray data, the complex has a ribbon-polymer structure determined by bidentate bridging type coordination of L to cadmium(II) atoms by N(3) and N(3s’) atoms. Tetramers of cadmium(II) atoms bonded by four bridging fu₂- and two fu₃-coordinated Cl atoms can be distinguished in the structure. The coordination polyhedron of cadmium(II) atoms is a distorted octahedron. The luminescent properties of L and dehydrated initial complex of the composition [Cd₂L(H₂O)(C₂H₅OH)Cl₄] _n are analyzed. It is shown that L has photoluminescence withλ_max = 477 nm in the blue spectral region, and the complex has photoluminescence in the yellow-orange range with λ_max = 577 nm at 300 K and λ_exc = 365 nm.     

Simplified Synthesis and Structural Study of { Ta6Br12} Clusters

Direct reaction of stoichiometric amounts of KBr, tantalum and bromine at 720 °C, followed by extraction and crystallization gives Ta₆Br₁₄ · 7H₂O (1) . This compound slowly aquates into [(Ta₆Br₁₂)(H₂O)₆]²⁺, which crystallized as mixed Cs⁺/Br^– ( 2 ), Cl^– ( 3 ) and SO₄^2– ( 4 ) salts. In Bu₄NBr melt, 1 undergoes oxidation into (Bu₄N)₂[(Ta₆Br₁₂)Br₆] ( 5 ). Reaction of 1 with dimethylsulfoxide also induces oxidation of the { Ta₆Br₁₂} ²⁺ core into { Ta₆Br₁₂} ⁴⁺, and the corresponding complex [(Ta₆Br₁₂)(dmso)₂Cl₄] · iPrOH · 4.8H₂O ( 6 ) was isolated and structurally characterized. Molecular and crystal structures for 2 – 6 were determined.     

Synthesis and crystal structure of Na2[RuNOCl5] · 6H2O

A procedure for the synthesis of Na₂[RuNOCl₅]·6H₂O is described. The complex was studied by IR spectroscopy and by thermal, X-ray phase, and X-ray diffraction analyses. Crystal data: a = 26.740(7), b = 31.581(7), c= 6.918(3) Å, V = 5842(3) ų space group Fdd2. Z = 16, d_calc= 2.103, d_exp = 2.112 g/cm³. The structure consists of [RuNOCl₅]^2? complex cations, Na⁺ cations, and crystallization water molecules. The compound is stable in conditions of high humidity of atmosphere but irreversibly loses up to four water molecules when stored in dry atmosphere. Removal of two water molecules is accompanied by crystal decay and changes in the crystal structure. Heating the substance above 100°C leads to a hygroscopic anhydrous complex Na₂[RuNOCl₅], which is stable below t = 375°C.     

Synthesis and study of Iron(II) perrhenate complexes with 4-propyl-1,2,4-triazole exhibiting 1A1 ? 5T2 spin transition

Coordination compounds of iron(II) perrhenate with 4-propyl-1,2,4-triazole (L), [Fe₃L₆(ReO₄)₄(H₂O)₂](ReO₄)₂(I), [Fe₃L₆(H₂O)₆](ReO₄)₆·H₂O(II), and FeL₃(ReO₄)₂(III), were synthesized. Compounds I and III were studied by static magnetic susceptibility measurements and by IR and electronic spectroscopy. These complexes exhibit a reversible ¹ A ₁ ⇄ ⁵ T ₂ spin transition and thermochromism. Compound I exhibits a spin transition without hysteresis at 185 K. The temperatures of forward and reverse transition for III are 250 and 244 K, respectively. Complex II isolated by crystallization from an acidified aqueous solution of compound I has a linear trinuclear structure of the cation (X-ray diffraction data). The structure of complex I was assumed to be similar, while compound III has a polymeric structure. Original Russian Text ? M.B. Bushuev, L.G. Lavrenova, Yu.G. Shvedenkov, A.V. Virovets, L.A. Sheludyakova, S.V. Larionov, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 1, pp. 51–56.     

A family of three-dimensional porous coordination polymers with general formula (Kat)2[{M(H2O)n}3{Re6Q8(CN)6}2]·xH2O (Q=S, Se; n=1.5, 2)

The X-ray crystal structures of a series of new compounds (H₃O)₂[{Mn(H₂O)_1.5}₃{Re₆Se₈(CN)₆}₂]·19H₂O (1), (Me₄N)₂[{Co(H₂O)_1.5}₃{Re₆S₈(CN)₆}₂]·13H₂O (2), (Me₄N)₂[{Co(H₂O)_1.5}₃{Re₆Se₈(CN)₆}₂]·3H₂O (3), (Et₄N)₂[{Mn(H₂O)₂}₃{Re₆Se₈(CN)₆}₂]·6.5H₂O (4), (Et₄N)₂[{Ni(H₂O)₂}₃{Re₆S₈(CN)₆}₂]·6.5H₂O (5), and (Et₄N)₂[{Co(H₂O)₂}₃{Re₆S₈(CN)₆}₂]·10H₂O (6) are reported. All six compounds are isostructural crystallizing in cubic space group with four formulae per unit cell. For compounds 1, 3-5 the following parameters were found: (1) a=19.857(2) Å, R1=0.0283; (3 at 150 K) a=19.634(1) Å, R1=0.0572; (4) a=20.060(2) Å, R1=0.0288; (5) a=19.697(2) Å, R1=0.0224. The structures consist three-dimensional cyano-bridged framework formed by cyano cluster anions [Re₆Q₈(CN)₆]⁴⁻, Q=S, Se and transition metal cations, M²⁺=Mn²⁺, Co²⁺, Ni²⁺. Water molecules and large organic cations Me₄N⁺ and Et₄N⁺ are included in cavities of this framework. Porosity of the framework, its ability to accommodate different cations and water molecules by little changes in the structure, as well as distortion of coordination framework under loss of water of crystallization is discussed.     

Redetermination of the crystal structure of potassium peroxodisulfate (K2S2O8)

The crystal structure of potassium peroxodisulfate was determined. The crystals are triclinic, a =5.115(1),b =7.034(2), c =5.505(1) å, α =106.32(2),gb =90.18(2), γ =106.12(2)?, V_cell = 181.90(7) å³, space group Pī, Z =1, d_calc =2.468 g/cm ³ [“Syntex P2₁,” λCuK_α, 994 reflections measured in a whole sphere to 2Τ_max =114?, including 496 independent reflections (R_int = 0.0571), R(F) = 0.0391, wR(F²) = 0.0933 for 486 F_hkl > 4Σ(F)]. An absorption correction (Μ = 171.37 cm^?1) was applied taking into account the shape and size of the crystal using data about face indices. The representative of the single crystal was proven by comparing the experimental and calculated diffractograms. The geometrical characteristics of S₂O ₈ ² : S-O 1.645(2), S = 0 1.421(3)-1.429(2), O-O 1.495(5) å, S-O-O 106.2(2)?.     

Reactivity of triangular oxalate cluster complexes [M<Subscript>3</Subscript>Q<Subscript>7</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>3</Subscript>]<Superscript>2−</Superscript> (M = Mo or W; Q = S or Se)

The reactions of the oxalate complexes [M₃Q₇(C₂O₄)₃]²⁻ (M = Mo or W; Q = S or Se) with Mn^II, Co^II, Ni^II, and Cu^II aqua and ethylenediamine complexes in aqueous and aqueous ethanolic solutions were studied. The previously unknown heterometallic complexes [Mo₃Se₇(C₂O₄)₃Ni(H₂O)₅]·3.5H₂O (1) and K₃{[Cu(en)₂H₂O]([Mo₃S₇(ox)₃]₂Br)}·5.5H₂O (2) were synthesized. In these complexes, the oxalate clusters serve as monodentate ligands. The K(H₂en)₂[W₃S₇(C₂O₄)₃]₂Br·4H₂O salt (3) was isolated from solutions containing Co^II, Ni^II, or Cu^II aqua complexes and ethylenediamine. The reaction of [Mo₃Se₇(C₂O₄)₃]²⁻ with HBr produced the bromide complex [Mo₃Se₇Br₆]²⁻, which was isolated as (Bu₄N)₂[Mo₃Se₇Br₆] (4). Complexes 1–3 were characterized by X-ray diffraction, IR spectra, and elemental analysis. The formation of 4 was detected by electrospray mass spectrometry. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1645–1649, September, 2007.