Reaktionen von Zink- und Cadmiumhalogeniden mit Tris(trimethylsilyl)phosphan und Tris(trimethylsilyl)arsan

Reactions of Zinc and Cadmium Halides with Tris(trimethylsilyl)phosphane and Tris(trimethylsilyl)arsane ZnCl₂ reacts with E(SiMe₃)₃ (E = P, As) in toluene in the presence of PⁿPr₃ to give the binuclear complexes [Zn₂Cl₂{E(SiMe₃)₂}₂(PⁿPr₃)₂] · C₇H₈ (E = P 1 , As 2 ). Therefore by the use of PⁱPr₃ clusters consisting of ten metal atoms are obtained, [Zn₁₀Cl₁₂(ESiMe₃)₄(PⁱPr₃)₄] (E = P 3 , As 4 ). As a result of the reaction of CdBr₂ with P(SiMe₃)₃ the compound [CdBr₂{P(SiMe₃)₃}]₂ ( 5 ) can be isolated at –40 °C. In the presence of PⁿPr₃ CdBr₂ reacts with P(SiMe₃)₃ forming the binuclear complex [Cd₂Br₂{P(SiMe₃)₂}₂(PⁿPr₃)₂] · thf ( 6 ). The same reaction with PⁱPr₃ yields to the cluster [Cd₁₀Br₁₂(PSiMe₃)₄{P(SiMe₃)₃}₄] · 2 C₇H₈ ( 7 ). ZnI₂ and CdI₂ react with As(SiMe₃)₃ to yield the complexes [MI₂{As(SiMe₃)₃}]₂ (M = Zn 8 , Cd 9 ). In the case of CdI₂ additionally the cluster [Cd₁₀I₁₂(AsSiMe₃)₄ · {As(SiMe₃)₃}₄] · 4,5 C₇H₈ ( 10 ) is formed which is analogous to the compounds 3 , 4 and 7 . In the presence of [PⁿBu₄]I 8  reacts in THF to give the ionic compound [PⁿBu₄]₂[Zn₆I₆(AsSiMe₃)₄(thf)₂] · C₆H₆ ( 11 ).     

Syntheses,crystal structures,and fluorescent properties of two Cd(II) complexes based on 2,2′-(ethane-1,2-diyl)bis(1H-imidazole-4,5-dicarboxylic acid)

Two new complexes, [Cd₂(H₄ebidc)₂(CH₃OH)₄]?·?2CH₃OH (1) and {[Cd(Cl)(I)(H₆ebidc)_1/2]?·?1/2bbe?·?H₂O} _n (2) (H₆ebidc?=?2,2′-(ethane-1,2-diyl)bis(1H-imidazole-4,5-dicarboxylic acid), bbe?=?1,2-bis(2-benzimidazolyl)ethane), are obtained through self-assembly of H₆ebidc with Cd(II). Single-crystal X-ray diffraction shows that 1 has a binuclear structure and each tridentate chelating ligand coordinates to two Cd(II) ions with µ₂-O. Complex 2 displays a 1-D chain structure and each tetradentate ligand bridges two Cd(II) ions in chelating fashion. Fluorescent properties have also been determined.     

pH-dependent synthesis of a cadmium coordination compound from a compound based on Hpytz ligand [Hpytz = 5-(4-pyridyl)tetrazole]

Reactions of CdSO₄·6H₂O and Hpytz [Hpytz = 5-(4-pyridyl)tetrazole] under high pH values produced a known compound, [Cd(pytz)₂(H₂O)₄]·2H₂O (1), which can be used to prepare [Cd(Hpytz)(SO₄)(H₂O)₂] (2) by adjusting the pH to a lower level using sulfuric acid under hydrothermal conditions. These compounds were characterized by elemental analysis, IR spectroscopy, and single-crystal diffraction. X-ray analysis reveals that 1 features a mononuclear structure, while 2 affords a 1-D polymeric chain structure. Compound 1 displays a 2-D network, while 2 shows a 3-D network by hydrogen bonding interactions. Furthermore, the luminescent properties were investigated at room temperature in the solid state.     

Self-assembly of three Cd(II) complexes: 0-D, 1-D,and 3-D structures based on 2-(1H-imidazol-1-methyl)-1 H-benzimidazole

Three new complexes, [Cd(L)I₂]₂ (1), {[Cd(L)I₂]?·?DMF} _n (2), and [Cd₂(L)₄(μ ₂-I)I(H₂O)] _n (3), have been obtained through self-assembly of an unsymmetrical ligand 2-(1H-imidazol-1-methyl)-1H-benzimidazole (L) with Cd(II) salts. Single-crystal X-ray diffraction shows that 1 displays a dimeric structure in which two Cd(II) ions are bridged by two bidentate bridging L. Complex 2 exhibits a 1-D chain structure (···Cd–L–Cd–L···) constructed by L bridging Cd(II) ions. In 3, the Cd(II) ions are five-connected nodes and linked by L and iodide leading to the 3-D network. Complexes 2 and 3 are synthesized maintaining the same solvents and stoichiometric ratio of metal and ligand at different reaction temperature. The different structures of the complexes indicate that the temperature plays a significant role in construction of the complexes. Luminescent properties of 1–3 have been investigated in the solid state at room temperature.     

ORGANIC PHOSPHORUS COMPOUNDS 70 PREPARATION AND PROPERTIES OF NEW PHOSPHORUS CONTAINING CHELATING AGENTS FOR CALCIUM AND MAGNESIUM IONS

Abstract

Dedicated to Professor Martin Schmeisser on the occasion of his 65th birthday.

Several phosphonic acids of the type H₂O₃PCH₂OCHRCO₂H, R = H, CH₃, CO₂H; [H₂O₃P(CH₂)_x]₂ Y, x = 1, 2; Y = O, S; and [o-H₂O₃P(CH₂)]₂C₆H₄ have been synthesized and their capacity to chelate with calcium has been determined.     

Syntheses and structural characterization of inorganic–organic hybrid solids of bis-imidazolium chlorocadmate complexes

Six organic–inorganic complexes derived from bis-imidazole derivatives ([(H₂L1)(CdCl₃ ? H₂O)₂] (1), L1 = 1-(3-(1H-benzimidazol-1-yl)propyl)-1H-benzimidazole; [(H₂L2)CdCl₄] (2), L2 = 1,1′-bis(benzimidazolyl)methane; [(H₂L3)CdCl₄] (3), L3 = 1-(2-(1H-benzimidazol-1-yl)ethyl)-1H-benzimidazole; [(H₂L4)₄(CdCl₄)₄] ? 13H₂O (4), L4 = 1,5-bis(1-benzimidazolyl)-3-oxapentane; [(H₂L5)CdCl₄] (5), L5 = 1-(4-(1H-benzimidazol-1-yl)butyl)-1H-benzimidazole; [(H₂L6)(Cd₂Cl₈)_0.5] ? H₂O (6), L6 = 3,6-bis(imidazol-1-yl)pyridazine), and cadmium(II) chloride dihydrate were prepared and characterized by IR, X-ray structure analysis, elemental analysis, and TG analysis. The imidazolyl moieties in all six compounds are essentially planar. X-ray diffraction analysis revealed that complexes 1–6 have 3-D network structures built from hydrogen bonds between imidazolium cations, chlorocadmate anions, and water. The arrangements of the anions and cations in their solid state are dominated not only by the size and symmetry of the imidazolium cations, but also by the different structure types of the chlorocadmate anions as well as the hydrogen-bonded interactions existing in the crystal structures. All of the complexes are thermally stable.     

Syntheses,structures, and properties of two 2-D Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole and polycarboxylate ligands

Two 2-D Cd(II) complexes, {[Cd(imb)(bdc)(H₂O)]·CH₃OH}_n (1) and {[Cd(imb)(Hbtc)(CH₃OH)]·2H₂O·CH₃OH}_n (2), have been synthesized by reactions of CdCl₂·2.5H₂O with 2-(1H-imidazol-1-methyl)-1H-benzimidazole (imb) and 1,3-benzenedicarboxylic acid (H₂bdc) or 1,3,5-benzenetricarboxylic acid (H₃btc). Single-crystal X-ray diffraction shows that 1 possesses an infinite 2-D layered structure in which all the carboxylates chelate Cd(II) and imb bridge Cd(II) ions. Complex 2 also features an infinite 2-D layered structure and imb ligands also bridge Cd(II) ions, but two carboxylates of each 1,3,5-benzenetricarboxylate coordinate to Cd(II) in monodentate or chelating mode, leaving the third one, which is not deprotonated, uncoordinated. IR spectra, fluorescent properties, and thermogravimetric analyses of both complexes have been investigated.