First Polynuclear Palladium Compounds [(C5H12NO)(PdCl3)]n and [(C10H16NO)2(Pd2Cl6)] with High Antitumor and Radioprotective Activity

Russian Journal of Coordination Chemistry - Polymeric palladium complexes [(C5H12NO)(PdCl3)]n (I) and [(C10H16NO)2(Pd2Cl6)] (II) were synthesized for the first time and studied by X-ray...     

Ring-opened 4-hydroxy-δ-valerolactone subunit as a key structural fragment of polyesters that degrade without acid formation

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Half-sandwich molybdenum complexes: molecular structure and catalyst precursors for olefin epoxidation with tert-butyl hydroperoxide

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Spontaneous Association of the Terbium Cyclopentadienyl Complexes under Controlled Hydrolysis

Controlled hydrolysis of the terbium cyclopentadienyl complexes results in the formation of the heteroligand tetranuclear terbium complex [{Tb(η⁵-C₅H₅)}₃{Tb(THF)₃}(μ₃-Cl)(μ₂-Cl)₆(μ₄-O)] (I), the recrystallization of which from tetrahydrofuran (THF) gives solvatomorph I · 0.5THF (Ia). According to the X-ray structure analysis data (CIF files CCDC 1569329 (I) and 1569330 (Ia)), the complexes are tetrahedral with the μ₄-bridging O^2– anion at the center of the tetrahedron. The cyclopentadienyl ligand in complex I is shown to act as an “antenna” providing luminescence of the complex.     

Peroxide derivatives of heteropoly compounds with Keggin anions [PW<Subscript>12</Subscript>O<Subscript>40</Subscript>]<Superscript>3−</Superscript> and [SiW<Subscript>12</Subscript>O<Subscript>40</Subscript>]<Superscript>4−</Superscript>: Synthesis and structure

Peroxide derivatives of heteropoly compounds with Keggin anions [PW₁₂O₄₀]^3? and [SiW₁₂O₄₀]^4? are isolated in an individual state from concentrated hydrogen peroxide solutions and characterized by physicochemical methods. The structure of Ba₂[SiW₁₂O₄₀] · 4H₂O₂ · 11H₂O (I) is solved by X-ray crystallography. Crystals of compound I (H₃₀Ba₂O₅₉Si₁W₁₂, FW = 3483.21) are monoclinic, space group C2/c, a = 24.981(2) Å, b = 12.2103(11) Å, c = 18.7142(17) Å, β = 122.620(2)^o, V = 4808.0(8) ų, Z = 4. The structure contains Keggin anions [SiW₁₂O₄₀]^4?; all hydrogen peroxide molecules are coordinated to Ba²⁺ cations.     

Synthesis and structures of new 1,3,6,2-dioxazaborocanes containing substituents in the ocane fragment

New 1,3,6,2-dioxazaborocanes R¹N(CHR³CR⁴R²O)(CHR⁶CHR⁵O)BX (1–11, X = Ph, 4-MeC₆H₄, Me; R¹ = Me, PhCH₂; R², R³, R⁴, R⁵, R⁶ = H, Ph) were synthesized by the reactions of aryl- or methylboronic acids with dialkanolamines. The treatment of (Me₂NCH₂CH₂O)₃B (15) with MeN(CH₂CH₂OH)(CH₂CPh₂OH) afforded 2-[2-(dime-thylamino)ethoxy]-1,3,6,2-dioxazaborocane (12). 2-Fluoro-1,3,6,2-dioxazaborocanes R¹N(CHR³CHR²O)(CH₂CH₂O)BF (13: R¹ = PhCH₂, R² = R³ = H; 14: R¹ = Me, R² = R³ = Ph, threo) were synthesized by the reaction of bis(trimethylsilyl) ethers of the corresponding dialkanolamines with BF₃·Et₂O. The new borocanes can be used for the synthesis of the corre-sponding germanium derivatives PhCH₂N(CH₂CH₂O)₂GeX₂ (16, X = OEt; 17, X = Cl), as exemplified by the reaction of compound 6. The structures of erythro-MeN(CH₂CH₂O)(CHPhCHPhO)BPh (3), threo-MeN(CH₂CH₂O)(CHPhCHPhO)BPh (4), erythro-MeN(CH₂CH₂O)(CHPhCHPhO)B(4-MeC₆H₄) (8), and PhCH₂N(CH₂CH₂O)₂BF (13) were established by X-ray diffraction. The coordination polyhedra of the boron atoms in these complexes can be described as distorted tetrahedra. The boron-nitrogen distances (1.705(7)–1.723(3) Å) provide unambiguous evidence for the presence of the B←N transannular interaction in these compounds. The structures of the resulting borocanes containing phenyl substituents at the carbon atoms of the ocane skeleton were studied by NMR spectroscopy and quantum chemical density functional theory calculations.     

Conformation of diethylglyoxime in uranyl complexes

New complexes of uranyl with diethylglyoxime have been synthesized and studied. A feature of these complexes is the tetradentate bridging coordination of the ligand in both cis- and trans-conformations. The structure of organic ligand C₆H₁₂N₂O₂ and binuclear complex (CN₃H₆)₄[(UO₂)₂(C₆H₁₀N₂O₂)(CO₃)(C₂O₄)₂] ? H₂O have been determined by X-ray diffraction.     

Synthesis of Tetrazino‐tetrazine 1,3,6,8‐Tetraoxide (TTTO)

This study presents the first synthesis and characterization of a new high energy compound [1,2,3,4]tetrazino[5,6‐e][1,2,3,4]tetrazine 1,3,6,8‐tetraoxide (TTTO). It was synthesized in ten steps from 2,2‐bis(tert‐butyl‐NNO‐azoxy)acetonitrile. The synthetic strategy was based on the sequential closure of two 1,2,3,4‐tetrazine 1,3‐dioxide rings by the generation of oxodiazonium ions and their intramolecular coupling with tert‐butyl‐NNO‐azoxy groups. The TTTO structure was confirmed by single‐crystal X‐ray.     

NO-disproportionation, promoted by Pd-cluster: formation and X-ray structure of Pd8(micro-CO)4(micro-OOCCMe3)8[micro-N(=O)O-]4

Interaction of Pd-clusters [Pd(CO)(OCOR)](n) with NO was investigated, these Pd-clusters were found to promote the NO disproportionation into N(2) and NO(2)(-) in mild conditions; an eight-nuclear palladium cluster Pd(8)(micro-CO)(4)(micro-OOCCMe(3))(8)(micro-NO(2))(4) with a new type of structure and an uncommon set of ligands was characterized by X-ray diffraction analysis.