Aromaticity, optical properties and zero field splitting of homo- and hetero-bimetallic (C8H8)M(μ2-,η8═C8H8)M(C8H8) where M = Ti, Zr, Th Complexes

This work presents a relativistic calculation of electron delocalization, optical properties, and zero field splitting in a group of molecules with the structure (C(8)H(8))M(μ(2)-,η(8)═C(8)H(8))M(C(8)H(8)), where M = Ti, Zr and Th. Additionally we also studied the heterobimetallic combinations (Ti-Th and Zr-Th). The molecular properties are discussed based on their electronic structure and the influence of the electron mobility in metal-metal communication. Nucleus independent chemical shift (NICS) was determined via the gauge-including-atomic-orbital (GIAO) method with the OPBE functional. The time-dependent density functional theory (TDDFT) was employed to calculate excitation energies, and the electronic transitions over 500 nm are presented with the objective to analyze the transition metal role as an antenna effect in the absorption band in the near-IR region. Finally the ZFS was calculated using Pederson-Khana and coupled perturbed DFT approaches implemented in the ORCA code. The contributions to spin-spin coupling (SS) and spin-orbit coupling (SOC) were analyzed, and the spin-density over the metal centers is discussed employing our scheme of metal-metal communication. Our aim is to determine the influence of the electronic structure over the optical and magnetic properties in a group of model compounds to understand the transition metals effect over these properties.     

Volume properties and refraction of aqueous solutions of bisadducts of light fullerene С60 and essential amino acids lysine,threonine, and oxyproline (С60(C6H13N2O2)2, С60(C4H8NO3)2, and С60(C5H9NO2)2) at 25°C

Concentration dependences of the density of aqueous solutions of bisadducts of light fullerene С₆₀ and essential amino acids are studied by pycnometry. Concentration dependences of the average molar volumes and partial volumes of components (Н₂О and corresponding bisadducts) are calculated for С₆₀(C₆H₁₃N₂O₂)₂–Н₂О, С₆₀(C₄H₈NO₃)₂–Н₂О, and С₆₀(C₅H₉NO₂)₂–Н₂О binary systems at 25°C. Concentration dependences of the indices of refraction of С₆₀(C₆H₁₃N₂O₂)₂–Н₂О, С₆₀(C₄H₈NO₃)₂–Н₂О, and С₆₀(C₅H₉NO₂)₂–Н₂О binary systems are determined at 25°C. The concentration dependences of specific refraction and molar refraction of bisadducts and aqueous solutions of them are calculated.

     

Complexation of N-Allyl Derivatives of Morpholinium with Copper(I) Halides: Synthesis and Crystal Structure of [C4H8ON(C3H5)2]+[Cu4Cl5]–, [C4H8ONH(C3H5)]+[CuBr2]–, and [C4H8ONH(C3H5)]+[CuBr1.41Cl0.59]–

The compounds [C₄H₈ON(C₃H₅)₂]⁺[Cu₄Cl₅]^– (I), [C₄H₈ONH(C₃H₅)]⁺[CuBr₂]^– (II), and [C₄H₈ONH(C₃H₅)]⁺[CuBr_1.41Cl_0.59]^– (III) were prepared for the first time by ac electrochemical synthesis from mono- and di-N-allyl derivatives of morpholinium and copper(I) halides in ethanol solution and structurally characterized. In the structure of I π-complex, the centrosymmetric Cu₈Cl₁₀ fragments are associated into layers perpendicular to the b axis. The N,N"-diallylmorpholinium cation functions as a bridge, which coordinates two copper atom of the adjacent inorganic fragments by both allyl groups. The trigonal-pyramidal surrounding of the Cu(I) atom, as well as the distorted tetrahedral coordination sphere of Cu(2), involves three chlorine atoms and the C=C bond, whereas the planar trigonal surrounding of the Cu(3) atom and trigonal-pyramidal surrounding of the Cu(4) atom involve only chlorine atoms. In the isostructural II and III σ-complexes, the edge-shared CuX₄ tetrahedra form the infinite copper-halide chains running along the a axis. The inorganic fragments and organic N-allylmorpholinium cations are united into the three-dimensional crystal structures by N–H···X and C–H···X (X = Cl, Br) hydrogen bonds.     

The Synthesis of the Arene Clusters Ru6C(CO)14(η6-Arene) (Arene = C6H5CHMe2, C6H5C4H9, C6H5C3H7, and C6H5C3H5)

On reaction with Ru₃(CO)₁₂, isopropenylbenzene and 4-phenyl-l-butene undergo hydrogenation, to yield the clusters, Ru₆C(CO)₁₄(⁶-C₆H₅CHMe₂) 1 and Ru₆C(CO)₁₄(⁶-C₆H₅C₄H₉) 2, respectively. With allylbenzene, both hydrogenation and isomerization occurs affording Ru₆C(CO)₁₄(⁶-C₆H₅C₃H₇) 3 and Ru₆C(CO)14(⁶-C₆H₅C₃H₅) 4. The structures of 1 and 2 have been established by single crystal X-ray diffraction. One of the Ru–Ru bond lengths in 2 is unusually long and extended Hückel molecular orbital calculations have been used in an attempt to rationalize this feature.     

Synthesis and structure of the organoantimony peroxide solvates [Sb4(μ2-O)4(O2)2(C6H3MeO-2,Br-5)8]·1.5C4H8O2 and [Sb4(μ2-O)4(O2)2(C6H3MeO-2,Br-5)8]·6C4H8O2

The organoantimony peroxide (Ar₂SbO)₄(O₂)₂ (Ar = C₆H₃OMe-2, Br-5) was synthesized by the oxidation of Ar3Sb with hydrogen peroxide in the presence or acetoxime or acetophenone oxime in dioxane. The product crystallizes with various content of the solvent molecules in the crystal unit cell [1.5 (I) and 6 (II), respectively]. An X-ray diffraction analysis of the solvates was performed. Four antimony atoms in the peroxide are in the octahedral coordination, and are linked through bridging oxygen atoms and two peroxide groups. The distances Sb-C, Sb-O_bridge, Sb-O_peroxide, O-O and Sb...Sb are 2.117–2.122, 1.960–1.972, 2.193–2.235, 1.461, 1.465 and 3.223–3.237 Å in I, and 2.112, 2.119, 1.957, 1,966, 2.204, 2,246, 1,467, and 3.2439 Å in II.     

Substitution and insertion reactions of (η5-C5H5)Cr(CO)3C2H5

The complex (η⁵-C₅H₅)Cr(CO)₃Cp42 H₅ has been made and its reactions with σ donor ligands L (L = (MeO)₃P and (EtO)₃P) and with SO₂ studied. The alkyl phosphites give compounds of the composition (η⁵-C₅H₅)Cr(CO)₂LC₂H₅, and sulfur dioxide gives the corresponding S-sulfinato (η⁵-C₅H₅)Cr(CO)₃SO₂C₂H₅.     

Synthesis and structure of [Zn8(HPO4)8(H2PO4)8]•[(C2H8N)8]•4H2O

A chain-like zincophosphate [Zn₈(HPO₄)₈(H₂PO₄)₈]•[(C₂H₈N)₈]•4H₂O was obtained at room temperature from a ZnO/P₂O₅/dimethylamine/H₂O mixture. The crystal structure was determined by single crystal X-ray diffraction. The symmetry is monoclinic a=1.26450(7)nm, b=1.08477(5)nm, c=1.46311(4)nm, β=98.793(5)°, space group Cc. The structure consists of chains of zinc-corner-sharing Zn₂P₂O₄ four rings. The negative charge of the chains is compensated by the protonated dimethylamine. The characterization by ³¹P solid state nmr spectroscopy is also reported.     

Theoretical study of aluminide clusters Al13X, Al13X−, and Al13X 2 − (X=H, Hal, OH, NH2, CH3, and C6H5)

The structural, electronic, energy, and vibrational characteristics of the Al₁₃X^? and Al₁₃X ₂ ^? clusters, with an aluminum-centered (Al_c) icosahedral cage Al₁₃ and with one or two outer-sphere ligands X=H, F, Cl, Br, OH, NH₂, CH₃, C₆H₅, have been calculated within the B3LYP approximation of the density functional theory using the 6-31G* and 6-311+G* basis sets. In all Al₁₃X^? radicals, the unpaired electron is localized at the cage atom Al* located opposite the Al-X bond. This Al* atom is the most favorable site for attaching the second X ligand of any nature (trans-addition rule). According to the previously suggested molecular model of the valence state of the [Al ₁₃ ^? ] “superatom,” the calculated energies D ₁(Al ₁₃ ^? -X) of addition of the first ligand to the Al ₁₃ ^? anion are about 1 eV lower than the corresponding energies of addition of the second ligand D ₂(XAl ₁₃ ^? -X). The structure of the Al₁₃ cage depends on the nature of the nature of the substituent X and can radically change in going from anions to their neutral congeners. In the lowest-lying Al₁₃X isomer with electronegative substituents X (Hal, OH, NH₂, CH₃, etc.), the aluminum cage has a marquee structure (1, symmetry C _s) with a hexagonal base and a pentagonal “roof.” For Al₁₃X analogues with electropositive ligands X (Al, Li, Na), a tridentate isomer (T, C _3v ) with the X substituent coordinated to a face of the Al₁₃ icosahedron is preferable. In the case of moderately electronegative X ligands (of the H type), the marquee (1) and icosahedral (T) isomers are close in energy. The stretching vibration frequencies of isomers 1 and T differ significantly in magnitude and intensity so that vibrational spectroscopy methods can be especially applicable to their experimental identification.     

Syntheses,crystal structures and antibacterial activities of [Cu2(C11H11NO5S)2(H2O)4] · 5H2O and [Ni2(C11H11NO5S)2(H2O)4] · 2H2O

The binuclear complexes [Cu₂L₂(H₂O)₄] · 5H₂O (1) and [Ni₂L₂(H₂O)₄] · 2H₂O (2) (where L = C₁₁H₁₁NO₅S, H ₂ L = 2-[(3-formyl-5-methyl-2-hydroxy-benzylidene)-amino]ethanesulfonic acid) have been synthesized and characterized by IR, elemental analysis and X-ray diffraction. The crystals belong to the monoclinic system, space group P2₁/c. Complex 1: a = 16.8902(12), b = 11.2829(6), c = 17.4249(11) Å; β = 106.709(4)°; S = 1.131; V = 3180.5(3) ų; Z = 4; D _Calcd = 1.729 g cm^?3; F(000) = 1712; μ = 1.554 mm^?1; R ₁ = 0.0519, wR ₂ = 0.1349; complex 2: a = 11.399(2), b = 19.985(3), c = 7.3694(10) Å; β = 108.664(7)°; S = 1.157; V = 1590.6(4) ų; Z = 2; D _Calcd = 1.604 g cm^?3; F(000) = 800; μ = 1.388 mm^?1; R ₁ = 0.1859, wR ₂ = 0.4346. The geometry around each metal(II) center can be described as slightly distorted octahedral. Water-sulfonic clusters and (H₂O)₄ water clusters can be observed for 1 from the crystal packing diagram, while cavity and offset face-to-face π–π stacking can be observed for 2. The complexes have been tested for the antibacterial activities which show antibacterial activities of 1 for β-hemolytic streptococcus, Staphylococcus aureus and Escherichia coli, and the antibacterial activity of 2 only for β-hemolytic streptococcus.     

Investigation of Copper Halide:Hydrothermal Syntheses and Characterization of CuBr2(C12H8N2) and Cu3Br3(C12H8N2)2

The reaction of CuBr₂ with 1,10‐phen‐H₂O (1,10‐phen = 1,10‐phenanthroline) gave two compounds: CuBr₂(C₁₂H₈N₂) and Cu₃Br₃(C₁₂H₈N₂)₂. Their structures have been characterized by single‐crystal X‐ray diffraction analysis, elemental analyses, thermogravimetric analyses (TGA) and measurement of variable temperature magnetic susceptibility. Crystal data for CuBr₂(C₁₂‐H₈N₂): monoclinic, space group P2₁/n, a = 0.9977(3) nm, b = 0.65138(14) nm, c = 1.8207(4) nm, β = 91.624(18)°, V = 1.1828(5) nm³, Z = 2. Crystal data for Cu₃Br₃(C₁₂H₈N₂)₂: monoclinic, space group C2/c, a = 1.00167(11) nm, b = 1.4523(4) nm, c = 1.6295(3) nm, β = 94.386(14)°, V = 2.3635(8) nm³, Z = 3.     

Cyclooctaselenadiazole: synthesis,decomposition pathway,and reaction with (η5-C5H5) Co(L)2 (L = C2H4, PPh3). Crystal and molecular structure of [(η5-C5H5)CO]2(μ2-η3,η2-C8H6Se)

Thermolysis of cyclooctaselenadiazole (2) yields only selenium-containing products. Compound 2 reacts with CpCo sources to give [(η⁵-C₅H₅)CO]₂(μ₂η³,η²-C₈H₆Se), a fluxional compound whose structure has been determined by X-Ray crystallography.     

Infrared investigations of the order–disorder ferroelectric phase transitions in imidazolium halogenobismuthates(III) and halogenoantimonates(III): (C3N2H5)5Bi2Cl11, (C3N2H5)5Bi2Br11 and (C3N2H5)5Sb2Br11

Infrared spectra of the powdered (C₃N₂H₅)₅Bi₂Cl₁₁, (C₃N₂H₅)₅Bi₂Br₁₁and (C₃N₂H₅)₅Sb₂Br₁₁ crystals in the region of internal vibrations of the imidazolium cations (3600 and 400 cm⁻¹) at the temperature intervals of 10–300 K, covering paraelectric–ferroelectric phase transitions, are presented and discussed in this paper. The research shows that the vibrational states of the imidazolium cations change markedly during the paraelectric–ferroelectric phase transition. The continuous nature of these transitions is well reflected in the infrared spectra, which is consistent with the previous X-ray and dielectric findings.     

Heats of formation of C(6)H(5)(•), C(6)H(5)(+), and C(6)H(5)NO by threshold photoelectron photoion coincidence and active thermochemical tables analysis

Threshold photoelectron photoion coincidence has been used to prepare selected internal energy distributions of nitrosobenzene ions [C(6)H(5)NO(+)]. Dissociation to C(6)H(5)(+) + NO products was measured over a range of internal energies and rate constants from 10(3) to 10(7) s(-1) and fitted with the statistical theory of unimolecular decay. A 0 K dissociative photoionization onset energy of 10.607 ± 0.020 eV was derived by using the simplified statistical adiabatic channel model. The thermochemical network of Active Thermochemical Tables (ATcT) was expanded to include phenyl and phenylium, as well as nitrosobenzene. The current ATcT heats of formation of these three species at 0 K (298.15 K) are 350.6 (337.3) ± 0.6, 1148.7 (1136.8) ± 1.0, and 215.6 (198.6) ± 1.5 kJ mol(-1), respectively. The resulting adiabatic ionization energy of phenyl is 8.272 ± 0.010 eV. The new ATcT thermochemistry for phenyl entails a 0 K (298.15 K) C-H bond dissociation enthalpy of benzene of 465.9 (472.1) ± 0.6 kJ mol(-1). Several related thermochemical quantities from ATcT, including the current enthalpies of formation of benzene, monohalobenzenes, and their ions, as well as interim ATcT values for the constituent atoms, are also given.     

Triethylaluminum-Based Ferrocenylalanes. Synthesis and Crystal Structure of (η5−C5H5)Fe[η5−C5H4Al2(C2H5)4Cl]

Abstract

The trietheylaluminum based ferrocenylalane (η⁵?C₅H₅)Fe[η⁵?C₅H₄Al₂(C₂H₅)₄Cl] was prepared from the reaction of triethylaluminum with chloromercuriferrocene in toluene and characterized by single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P 1 with unit cell dimensions a = 9.353(3) Å, b = 10.281(7) Å, c = 11.599(9) Å, α = 79.64(7)°, β = 69.41(6)°, γ = 84.33(4)°, and Z = 2 for D_c = 1.27 g cm^?3. Full-matrix least-squares refinement has led to a final R factor of 0.068 based on 1866 independent observed reflections. The two diethylaluminum units are bridged by a chlorine atom and one carbon atom of a cyclopentadienyl group, thus forming an Al-Cl-Al-C ring. The four-membered ring is planar to within 0.02 Å. The Al-Cl distances are 2.404(4) Å and 2.266(5) Å. The Al-Cl-Al angle is 78.9(1)° while the Al-C-Al angle is 91.3(4)°. No significant aluminum-iron interaction is observed (Al… Fe = 3.137(4) Å).     

固态配合物RE(C5H8NS2)3(C12H8N2)的光谱性质

在无水乙醇中, 合成了组成为RE(C5H8NS2)3(C12H8N2) (RE=La, Pr, Nd, Sm～Lu) 的固态配合物. IR光谱表明配合物中稀土离子(RE3 )与吡咯烷二硫代氨基甲酸铵 (APDC)中的硫原子和1, 10-邻菲咯琳(o-phen) 中的氮原子均双齿配位; UV光谱显示配合物中o-phen与稀土离子之间的能量传递是主要过程, 配合物的最大吸收与o-phen相比有微小的红移; FS光谱表明配合物Sm(C5H8NS2)3(C12H8N2)和Eu(C5H8NS2)3(C12H8N2)具有很强的荧光性质.     

Thermal decomposition of Ln(C2H5CO2)3·H2O (Ln?=?Ho, Er, Tm and Yb)

The thermal decomposition of Ho(III), Er(III), Tm(III) and Yb(III) propionate monohydrates in argon was studied by means of thermogravimetry (TG), differential thermal analysis (DTA), IR-spectroscopy and X-ray diffraction (XRD). Dehydration takes place around 90?°C. It is followed by the decomposition of the anhydrous propionates to Ln₂O₂CO₃ (Ln?=?Ho, Er, Tm or Yb) with the evolution of CO₂ and 3-pentanone (C₂H₅COC₂H₅) between 300 and 400?°C. The further decomposition of Ln₂O₂CO₃ to the respective sesquioxides Ln₂O₃ is characterized by an intermediate plateau extending from approximately 500?C700?°C in the TG traces. This stage corresponds to an overall composition of Ln₂O_2.5(CO₃)_0.5 but is more probably a mixture of Ln₂O₂CO₃ and Ln₂O₃. The stability of this intermediate state decreases for the lighter rare-earth (RE) compounds studied. Full conversion to Ln₂O₃ is achieved at about 1,100?°C. The overall thermal decomposition behaviour of the title compounds is similar to that previously reported for Lu(C₂H₅CO₂)₃·H₂O.     

Synthesis, characterization and standard molar enthalpy of formation of Nd(C7H5O3)2·(C9H6NO)

The complex from reaction of neodymium chloride six-hydrate with salicylic acid and 8-hydroxyquinoline, Nd(C₇H₅O₃)₂·(C₉H₆NO), was synthesized and characterized by IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [NdCl₃·6H₂O(s)], [2C₇H₆O₃(s)], [C₉H₇NO(s)] and [Nd(C₇H₅O₃)₂·(C₉H₆NO)(s)] in a mixed solvent of anhydrous ethanol, dimethyl formamide (DMF) and perchloric acid were determined by calorimetry at 298.15 K. Based on Hess’ law, a new chemical cycle was designed, and the enthalpy change of the reaction

Vibrational spectra in the ν(SiH) and ν(SiD) regions of chloro and bromodisilanes and ab initio geometry studies of C2H5Cl,Si2H5Cl and 1,1-Si2H4Cl2

Infrared measurements in the gas phase are reported for the ν(SiH) and ν(SiD) regions of Si₂H₅X, Si₂D₅X, 1,1-Si₂H₄X₂ and 1,1-Si₂D₄X₂ species where X = Cl, Br. Incomplete Raman data have also been obtained. All three possible isolated SiH stretching frequencies are observed in the spectra of the Si₂D₄X₂ samples, but only two from the Si₂D₅X ones. The missing ν^is(SiH) values are obtained by use of the frequency sum rule, and by harmonic local mode force field treatments of all the available ν(SiH) and ν(SiD) data, using a procedure previously tested on disilane.Ab initio calculations of the geometries of C₂H₅Cl, Si₂H₅Cl and 1,1-Si₂H₄Cl₂ using the 6-31G* basis set are reported. Trends in r_e(CH) or r_e(SiH) values reflect trends in ν^is(CH) or ν^is(SiH) ones. The alpha, trans and gauche effects of halogen are similar in CH and SiH compounds, although smaller in the latter. In both cases, ab initio calculations predict larger effects than are observed in the spectra, especially for the α effect of halogen.A kinetic isotope effect in the halogenation of disilane may occur. Reassignment of earlier spectra of disilyl iodide species is proposed.     

Thermal decomposition of RE(C2H5CO2)3·H2O (RE = Dy,Tb, Gd,Eu and Sm)

The thermal decomposition of Dy(III), Tb(III), Gd(III), Eu(III), and Sm(III) propionate monohydrates was studied in argon by means of simultaneous differential thermal analysis and thermogravimetry, infrared-spectroscopy, X-ray diffraction, and optical microscopy. After dehydration, which takes place below 120 °C, all salts decompose into dioxycarbonates with simultaneous release of CO₂ and C₂H₅COC₂H₅ (3-pentanone) between 250 and 460 °C. However, whereas the anhydrous Dy-, Tb-, and Gd-propionates appear to transform into RE₂O₂CO₃ (rare earth [RE] = Dy, Tb, Gd) in a single step, an intermediate stage involving a RE₂O(C₂H₅CO₂)₄ composition was evidenced in the case of the Eu- and Sm-propionates. For all compounds, further decomposition of RE₂O₂CO₃ into the corresponding sesquioxides (RE₂O₃) is accompanied by the release of CO₂. The thermal decomposition of Dy- and Tb-propionates occurs entirely in the solid state. In contrast the dehydrated Gd-, Eu-, and Sm-propionates melt at increasingly higher temperatures. Evidence for recrystallization was found in conjunction with the onset of decomposition of these three propionates.