Complexes of metallons with phosphorus or arsenic containing ligands. II. complexes ortho-carboxyphenyltertiaryarsines with mercury (II) halides

Ortho-carboxyphenyl-dimethylarsine (CPDMA), ortho-carboxpyhenyldiphenylarsine (CPDPA) and ortho-carboxyphenyldi(p-tolyl)arsine (CPDTA) react with mercury(II) halides to yield complexes having the formula HgX₂L where X is Cl, Br or I and L is ligand. In view of infrared spectral data these complexes have been classified into two classes: (a) those in which the carboxyl group of the ligand remains free (ligand being monodentate), and (b) those in which the ligand acts as a bidentate group. The complex Hg(Cl₂) · CPDPA is the only example of type (a) and has been assigned a dimeric halogen bridged structure. The remaining eight complexes are assumed to be monomeric. A tetrahedral structure is proposed for all the nine complexes.     

[Be3(μ3‐O)3(MeCN)6{Be(MeCN)3}3](I)6 – ein Berylliumkomplex mit Cyclo‐(Be3O3)‐Kern und sein Hydrolyseprodukt [Be(H2O)4](I)2·2MeCN

Single crystals of [Be₃(μ₃‐O)₃(MeCN)₆{Be(MeCN)₃}₃](I)₆·4CH₃CN ( 1 ·4CH₃CN) were obtained in low yield by the reaction of beryllium powder with iodine in acetonitrile suspension, which probably result from traces of beryllium oxide containing the applied beryllium metal. The compound 1 ·4CH₃CN forms moisture sensitive, colourless crystal needles, which were characterized by IR spectroscopy and X‐ray diffraction (Space group Pnma, Z = 4, lattice dimensions at 100(2) K: a = 2317.4(1), b = 2491.4(1), c = 1190.6(1) pm, R₁ = 0.0315). The hexaiodide complex cation 1 ⁶⁺consists of a cyclo‐Be₃O₃ core with slightly distorted chair conformation, stabilized by coordination of two acetonitrile ligands at each of the beryllium atoms and by a {Be(CH₃CN)₃}²⁺ cation at each of the oxygen atoms. This unique coordination behaviour results in coplanar OBe₃ units with short Be–O distances of 155.0 pm and 153.6 pm on average of bond lengths within the cyclo‐Be₃O₃ unit and of the peripheric BeO bonds, respectively. Exposure of compound 1 ·4CH₃CN to moist air leads to small orange crystal plates of [Be(H₂O)₄]I₂·2CH₃CN ( 3 ·2CH₃CN). According to the crystal structure determination (Space group C2/c, Z = 4, lattice dimensions at 100(2) K: a = 1220.7(1), b = 735.0(1), c = 1608.5(1) pm, β = 97.97(1)°, R₁ = 0.0394), all hydrogen atoms of the dication [Be(H₂O)₄]²⁺ are involved to form O–H ··· N and O–H ··· I hydrogen bonds with the acetonitrile molecules and the iodide ions, respectively. Quantum chemical calculations (B3LYP/6‐311+G**) at the model [Be₃(μ₃‐O)₃(HCN)₆{Be(HCN)₃}₃]⁶⁺ show that chair and boat conformation are stable and that the distorted chair conformation is stabilized by packing effects.     

Thermal stability of new zinc acetate-based complex compounds

New zinc acetate based complex compounds (of general formula Zn(CH₃COO)₂·1?2L·nH₂O) containing one or two molecules of urea, thiourea, coffeine and phenazone were prepared namely: Zn(CH₃COO)₂·2.5H₂O, Zn(CH₃COO)₂·2u·0.5H₂O, Zn(CH₃COO)₂·tu·0.5H₂O, Zn(CH₃COO)₂·2tu, Zn(CH₃COO)₂·cof·2.5H₂O, Zn(CH₃COO)₂·2cof·3.5H₂O, Zn(CH₃COO)₂·2phen·1.5H₂O. The compounds were characterized by IR spectroscopy, chemical analysis and thermal analysis. Thermal analysis showed that no changes in crystallographic modifications of the compounds take place during (heating in nitrogen before) the thermal decompositions. The temperature interval of the stability of the prepared compounds were determined. It was found that the thermal decomposition of hydrated compounds starts by the release of water molecules. During the thermal decomposition of anhydrous compounds in nitrogen the release of organic ligands take place followed by the decomposition of the acetate anion. Zinc oxide and metallic zinc were found as final products of the thermal decomposition of the zinc acetate based complex compounds studied. Carbon dioxide and acetone were detected in the gaseous products of the decomposition of the compounds if ZnO is formed. Carbon monoxide and acetaldehyde were detected in the gaseous products of the decomposition, if metallic Zn is formed. It is supposed that ZnO and Zn resulting from Zn acetate complex compounds here studied, possess different degree of structural disorder. Annealing takes place by further heating above 600°C.     

Adducts of tetraphenylstibium nitrate with nitric acid and of tetraphenylstibium acetate with acetic acid: Syntheses and structures

The reactions of tetraphenylstibium nitrate with nitric acid and of tetraphenylstibium acetate with acetic acid yield adducts Ph₄SbONO₂ · HNO₃ (I) and Ph₄SbOC(O)CH₃ · CHH₃COOH (II). According to X-ray diffraction data, the antimony atom in [Ph₄Sb]⁺[O₂N-O···H···O-NO₂]^? has a tetrahedral coordination. The CSbC bond angles and Sb-C bond lengths vary within 108.04(6)°–109.75(4)° and 2.096(1)–2.098(1) Å, respectively. The anion includes the intermolecular hydrogen bond O(1)–H(1)···O(1)″: the O(1)-H(1), H(1)···O(1)″, and O(1)···O(1)″ distances are 0.91(4), 1.56(4), and 2.460(2) Å, respectively; and the OHO angle is 169(5)°. The nitrate groups are usually planar. Complex II also contains the intermolecular hydrogen bond with the following parameters: O(3)-H(3), 0.92 Å; H(3)···O(2), 1.68 Å; and O(3)···O(2) 2.594 Å; the O(2)H(3)O(3) angle is 172.1°. This H-bond noticeable changes the coordination polyhedron of the antimony atom compared to that in tetraphenylstibium acetate.     

Stabilisation of copper(II) tertiary-phosphine or -arsine complexes—II. Role of inductive effect and reaction conditions in stabilising copper(II)-arsine complexes of hybrid oxygen-arsenic ligands from o-R2AsC6H4CO2H

The characterization of the products of reactions between anhydrous/hydrated copper(II) acetate and the title acids having R = Me, C₆H₁₁, Ph and p-tolyl in different solvents and at different temperatures with the help of elemental analysis, TGA, DTA, room temperature magnetic susceptibility, IR, and UV-VIS and EPR spectral data reveal that a competition exists between the chelation of arsine to copper(II) on one side and the reduction of copper(II) to copper(I) and the subsequent chelation of the arsine to copper(I) and/or that of the arsine oxide to copper(II) on the other. This competition which is expected to be normally governed by the inductive effect of group R is disturbed by the change in reaction conditions leading to the conclusion that the reaction conditions rather than the inductive effect of the group R control the mode of reaction.     

Sensitive spectrophotometric determination of beryllium with Eriochrome Cyanine R and cetyltrimethylammonium ions

In the presence of cetyltrimethylammonium ions (CTA) a significant bathochromic shift in the color reaction of beryllium with Eriochrome Cyanine R (ER) takes place. This is accompanied by a nearly trifold increase in the sensitivity. The triple complex of beryllium with Eriochrome Cyanine R and CTA (in which the molar ratio of Be:ER is 1:2) is proposed as a basis of a new sensitive spectrophotometric method of beryllium determination. The molar absorptivity ? = 8.65 × 10⁴ at λ_max = 590 nm, pH ~ 7 (borate buffer), when the solution is heated at 60 °C for 15 min. The method is very selective when EDTA is used as a masking agent. EDTA does not affect the formation of the triple beryllium complex neither do tartrate, citrate, and acetate. Phosphate and fluoride interfere.     

Influence of the precursor salts in the synthesis of CaSnO<Subscript>3</Subscript> by the polymeric precursor method

CaSnO₃ was synthesized by the polymeric precursor method, using different precursor salts as (CH₃COO)₂Ca·H₂O, Ca(NO₃)₂·4H₂O, CaCl₂·2H₂O and CaCO₃, leading to different results. Powder precursor was characterized using thermal analysis. Depending on the precursor different thermal behaviors were obtained. Results also indicate the formation of carbonates, confirmed by IR spectra. After calcination and characterization by XRD, the formation of perovskite as single phase was only identified when calcium acetate was used as precursor. For other precursors, tin oxide was observed as secondary phase.     

Design of novel podand-like compounds with two short diphenylphosphine oxide pendant arms

Crystal and molecular structure of 1,3,5-benzenetris(methylenediphenylphosphine oxide) cyclohexylammonium chloride dibenzene solvate monohydrate has been determined. The overall arrangement of two diphenylphosphine oxide substituents atoms is imposed by intermolecular strong hydrogen bonds, O_(water) H···O_(oxide) and N H···O_{(oxide, water)}. Cyclohexylamine exists in almost ideal chair conformation and nitrogen atom is equatorial to the ring. The structure is build up from strong and weak intermolecular hydrogen bonds to form the three-dimensional infinite hydrogen bond network. Crystal and molecular structure of 1,4-bis[(diphenylphosphineoxide)methyl] - 2,5 - bis (ethoxymethyl) benzene has been determined. The phenyl rings are inclined at 80.91(7)° within the substituent, and they are involved in weak C_(phenyl) H···O_(oxide) hydrogen bonds. The arrangement of diphenylphosphine oxide substituents is imposed practically only by steric effects. Two intramolecular weak hydrogen bonds exist between diphenylphosphine oxide and ethoxymethyl substituents, which can provide additional stabilization to molecule, but it has no noticeable influence on overall molecule geometry. Molecules are assembled via weak intermolecular C H···O_(oxide) hydrogen bonds to the one-dimensional hydrogen-bonded chain along y axis. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:233–240, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20008     

Analytical application of embelin

Summary Embelin is employed as a analytical reagent for the estimation of (a) aluminium in solutions of p_H 4.0–4.5 and (b) beryllium in solutions of p_H 6.5–7.0. While aluminium could be estimated both as its complex or as oxide, Al₂O₃, beryllium could be estimated only as oxide, BeO. The reagent is also employed for the separation of beryllium from aluminium.Part I: See Z. analyt. Chem. 175, 114 (1960).     

Gravimetric determination of beryllium with n-benzoylphenylhydroxylamine

N-Benzoylphenylhydroxylamine has been employed in the gravimetric determination of beryllium and in its separation from iron, aluminium and titanium. After suitable adjustment of pH iron, aluminium or titanium is precipitated quantitatively with the reagent; beryllium is subsequently precipitated after raising the pH of the filtrate. The metal may be determined by either igniting the precipitate to beryllium oxide or weighing it as Be(C₁₃H₁₀O₂N)₂.     

The Solid-state Structures of a Non-hydrated Yttrium Carboxylate and a Yttrium Carboxylate Hemihydrate Obtained by Reaction of Yttrium Alkoxides with Carboxylic Acids

The yttrium carboxylates Y(methacrylate)₃ and Y(acetate)₃·0.5 H₂O were prepared by reaction of Y(OCH₂CH₂OMe)₃ with methacrylic or acetic acid and characterized by X-ray structure analyses. Both carboxylates have chain structures with both bridging and chelating-bridging carboxylate ligands. In Y(acetate)₃·0.5 H₂O, every second yttrium atom is nine-coordinate due to the additional coordination of a water molecule.     

A theoretical study of three and four proton donors on linear HX···BeH2···HX and bifurcate BeH2···2HX trimolecular dihydrogen-bonded complexes with X?=?CN and NC

The interaction phenomenon H^−δ···H^+δ between two hydrogen atoms binding each other is well-known in dihydrogen-bonded complexes. Either by experimental or theoretical viewpoint, dihydrogen bonds are often known as directional or bifurcate interactions. Regarding the beryllium hydride BeH₂, its capacity to form bimolecular complexes with proton donors has been demonstrated, but in some cases, trimolecular complexes are also characterized in a minimum of the potential energy surface. As such, in this work is presented a theoretical study about the formation of trimolecular dihydrogen complexes with three hydrogen centers. By taking into account the beryllium hydride BeH₂ as proton acceptor, two classical proton donors were chosen, HCN and HNC. The great goal of this work is the analysis of two dihydrogen complexes types: bifurcate BeH₂···2HX and linear HX···BeH₂···HX. In these systems, it is discussed the capacity of one hydride H^−δ (H–Be–H^−δ) to interact simultaneously with two proton donors, as well as when two hydrides H^−δ (^−δH–Be–H^−δ) form linear dihydrogen bonds. In this context, the analysis of the vibrational harmonic spectrum at B3LYP/6-311 ++G(3d,3p) level of theory and the interpretation of the topological parameters derived from Quantum Theory of Atoms in Molecules (QTAIM) aided us to determine which is the most stable trimolecular complex, either bifurcate or linear. Moreover, quantification of charge transfer measured by the QTAIM formalism as well as by ChelpG calculations also were used with the purpose to justify infrared effects, such as red-shift and blue-shift stretch modes on donors (HCN and HNC) and acceptors (BeH₂) of protons.     

Copolymerization of carbon dioxide with cyclohexene oxide catalyzed by bimetallic dysprosium complexes containing hydrazine‐functionalized Schiff‐base derivatives

A series of dinuclear Dy^III acetate complexes containing three different hydrazine‐functionalized Schiff‐base ligands ( hmb , hmi, and hb ) have been synthesized by one‐pot reaction with Dy(OAc)₃·4H₂O as the metal precursor. [Dy₂( hmb )₂(OAc)₄]·MeCN ( 1 ·MeCN) and [Dy₂( hmi )₂(OAc)₂(MeOH)₂]·H₂O ( 2 ·H₂O) with keto and enol forms of the corresponding ligands, respectively, were shown the similar core structures but different ratio of Dy^III to OAc^–. Moreover, the different coordination environments of complex [Dy₂( hb )₂(μ‐OAc)₂(OAc)₂(H₂O)₂]·DMF·H₂O ( 3 ·DMF·H₂O) also offered an opportunity to understand the relationship between structural model and catalytic properties. Bimetallic dysprosium complexes 1 – 3 were demonstrated to be active catalysts for copolymerization of carbon dioxide (CO₂) and cyclohexene oxide (CHO) without cocatalysts. To the best of our knowledge, well‐defined catalyst 2 appears to be the first example of an air‐stable bimetallic dysprosium complex that is effective for CO₂/CHO copolymerization and the formation of the perfectly alternating poly(cyclohexenecarbonate) with a high molecular weight. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 321–328     

Two crystals of doubly protonated melaminium salts: melaminium bis­(trifluoro­acetate) trihydrate and melaminium bis­(trichloro­acetate) dihydrate

Crystals of 2,4,6‐triamino‐1,3,5‐triazine‐1,3‐dium bis­(trifluoro­acetate) trihydrate, C₃H₈N₆²⁺·2CF₃COO⁻·3H₂O, and 2,4,6‐triamino‐1,3,5‐triazine‐1,3‐dium bis­(trichloro­acetate) dihydrate, C₃H₈N₆²⁺·2CCl₃COO⁻·2H₂O, both contain doubly protonated melamine rings that lie on crystallographic twofold axes. In the former structure, one water mol­ecule also lies on a twofold axis. While the trifluoro­acetate compound crystallizes in a centrosymmetric space group, the trichloro­acetate is non‐centrosymmetric, so it is useful as a material for non‐linear optics. The efficiency of second harmonic generation is about three times greater than that of KDP (KH₂PO₄). A combination of ionic and donor–acceptor hydrogen‐bond inter­actions link the melaminium(2+) residues with trifluoro­acetate or trichloro­acetate ions and water mol­ecules to form a three‐dimensional network.     

The Solid-state Structures of a Non-hydrated Yttrium Carboxylate and a Yttrium Carboxylate Hemihydrate Obtained by Reaction of Yttrium Alkoxides with Carboxylic Acids

Summary. The yttrium carboxylates Y(methacrylate)₃ and Y(acetate)₃·0.5 H₂O were prepared by reaction of Y(OCH₂CH₂OMe)₃ with methacrylic or acetic acid and characterized by X-ray structure analyses. Both carboxylates have chain structures with both bridging and chelating-bridging carboxylate ligands. In Y(acetate)₃·0.5 H₂O, every second yttrium atom is nine-coordinate due to the additional coordination of a water molecule.     

Organic Derivatives of Tin. III. Reactions of Trialkyltin Ethoxide with Alkanolamines

The reactions oi tributyltin ethoxide, Bu₃SnOEt, with N,N-dialkylalkanolamines, HORNR₂ (where R = ? CH₂ · CH₂? , ? CH₂ · CH₂ · CH₂? and ? CH₂ · MeCH? ; R = ? CH₃ and ? C₂H₅) give Bu₃SnORNR₂. In reactions of Bu₃SnOEt with N-methylethanolamine, HOCH₂ · CH₂NHMe, and various alkanolamines, HO · R · NH₂, (where R = ? CH₂ · CH₂? ? CH₂ · CH₂ · CH₂? , ? CHMe · CH₂? ? CH₂ · Me₂C? and ? CH₂ · CH · CH₂ · Me) both the hydroxy as well as the amino groups show reactivity to form products of the type: Bu₃SnOCH₂ · CH₂NHMe, Bu₃SnOCH₂ · CH₂NMeSnBu₃, Bu₃SnO · R · NH₂, Bu₃SnO · R · NHSnBu₃, and Bu₃SnO · R · N(SnBu₃)₂, respectively. The reaction between Bu₃SnOEt and o-aminophenol yields only Bu₃SnO · C₆H₄NH₂.     

Copper(II) Complex of a Urea-functionalized Pyridyl Ligand: Synthesis,Crystal Structure,and Acetate Binding Properties

A copper(II) acetate complex with a urea-functionalized pyridyl ligand, [CuL(OAc)₂]₂ · 2AcOH ( 1 ) [L = N-(3-chlorophenyl)-N'-(3-pyridyl) urea], was synthesized by the reaction of L with Cu(OAc)₂ in methanol. A zigzag-shaped hydrogen bond chain of L is obtained via urea N–H ··· N_pyridyl interactions, and a two-dimensional hydrogen bond network structure is further formed through the C–H ··· O interaction. In the complex 1 , a paddle-wheel structure is generated by Cu ··· O_acetate interactions and Cu ··· N_pyridyl interactions. Furthermore, hydrogen bonding chain structure is extended through weak C–H ··· O hydrogen bond interactions. Through ultraviolet-visible (UV/Vis) spectroscopy, the acetate binding properties of L in solution were also evaluated. Variable temperature magnetic susceptibility measurement indicates that the metal complex 1 displays antiferromagnetic coupling property.     

Ruthenium complexes containing group 5b donor ligands : Part VII. Rearrangement reactions of some ruthenium (II) complexes containing triphenylphosphine,tri-p-tolylphosphine or ethyldiphenylphosphine ligands.

As for [RuCl₂(PPh₃₃], carbonylation of [RuCl₂(PR₃)₃] [PR₃ = P(p-tolyl)₃, PEtPh₂) in N,N ¹-dimethylformamide (dmf) gives [Ru(CO)Cl₂ (dmf) (PR₃)₂] (II). For PR₃ = PEtPh₂, rearrangement of (II) in various solvents gives inseparable mixtures (³¹P evidence) but for PR₃ = P(p-tolyl)₃ [Ru₂(CO)₂Cl₄-{P(p-tolyl)₃}₃]is obtained. Reaction of [Ru(CO)Cl₂ (dmf) - {P(p-tolyl)₃}₂] with [RuCI₂{(P(p-tolyl)₃}₃] (1:1 mol ratio) gives [Ru₂ (CO) Cl₄ {P (p-tolyl)₃}₄] whereas reaction of [Ru (CO) Cl₂ (dmf) - (PPh₃₂] with (Rul₂ {P (p-tolyl)₃}₃] gives [Ru₂(CO)Cl₄ (PPh₃)₂] - {P(p-tolyl)₃}₂] - Reaction of [RuCl₂ {P(p-tolyl)₃}₃] with CS₂ gives the related [Ru₂Cl₄(CS) {P(p-tolyl)₃}₄] and [{RuCl₂(CS)}P(p-tolyl)₃{₂}₂] whereas [RuCl₂(PEtPh₂)₃] and CS₂ produce [RuCl₂(S₂CPEtPh₂) (PEtPh₂)₂]CS₂ and [Ru₂Cl₄(CS)₂(PEtph₂)₃].     

Etude par thermogravimetrie,analyse thermique differentielle et spectrographie d'absorption infra-rouge de la reaction du peroxyde de sodium sur l'oxyde de Beryllium

Thermogravimetric and differential thermal methods as well as chemical analysis show that sodium peroxide attacks beryllium oxide to form beryllate, apparently in the molecular ratio 1 Na₂O:1 BeO. An unidentified peroxy compound of beryllium is formed at about 165° by the action of the NaO² present in the Na₂O₂ sample; it decomposes between 280 and 310°. IR absorption spectroscopy indicates the presence of Be-O bonds in the sodium beryllate which are different from those in the oxide used.