Syntheses, thermal stability, and structure determination of the novel isostructural RBa3B9O18 (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb)

A novel borate compound YBa(3)B(9)O(18) has crystallized in a melt of BaYB(9)O(16). Single-crystal X-ray diffraction measurements reveal that YBa(3)B(9)O(18) adopts a hexagonal space group P6(3)/m with cell parameters of a = 7.1761(6) A and c = 16.9657(6) A. The structure is made up of the planar B(3)O(6) groups parallel to each other along the (001) direction, regular YO(6) octahedra, and irregular BaO(6) and BaO(9) polyhedra to form an analogue structure of beta-BaB(2)O(4). A series of isostructural borate compounds RBa(3)B(9)O(18) (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were prepared by powder solid-state reactions. The DTA and TGA curves of YBaB(9)O(16) show an obvious weight loss at about 955 degrees C associated with a decomposition into YBO(3), B(2)O(3), and YBa(3)B(9)O(18) due to its incongruent melting behavior. The DTA and TGA curves of YBa(3)B(9)O(18) show that it is chemically stable and a congruent melting compound. A comparison of the structures of YBa(3)B(9)O(18) and beta-BaB(2)O(4) is presented.     

Syntheses, structure, and selected physical properties of CsLnMnSe3 (Ln = Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y) and AYbZnQ3 (A = Rb, Cs; Q = S, Se, Te)

CsLnMnSe(3) (Ln = Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y) and AYbZnQ(3) (A = Rb, Cs; Q = S, Se, Te) have been synthesized from solid-state reactions at temperatures in excess 1173 K. These isostructural materials crystallize in the layered KZrCuS(3) structure type in the orthorhombic space group Cmcm. The structure is composed of LnQ(6) octahedra and MQ(4) tetrahedra that share edges to form [LnMQ(3)] layers. These layers stack perpendicular to [010] and are separated by layers of face- and edge-sharing AQ(8) bicapped trigonal prisms. There are no Q-Q bonds in the structure of the ALnMQ(3) compounds so the formal oxidation states of A/Ln/M/Q are 1+/3+/2+/2-. The CsLnMnSe(3) materials, with the exception of CsYbMnSe(3), are Curie-Weiss paramagnets between 5 and 300 K. The magnetic susceptibility data for CsYbZnS(3), RbYbZnSe(3), and CsYbMSe(3) (M = Mn, Zn) show a weak cusp at approximately 10 K and pronounced differences between field-cooled and zero-field-cooled data. However, CsYbZnSe(3) is not an antiferromagnet because a neutron diffraction study indicates that CsYbZnSe(3) shows neither long-range magnetic ordering nor a phase change between 4 and 295 K. Nor is the compound a spin glass because the transition at 10 K does not depend on ac frequency. The optical band gaps of the (010) and (001) crystal faces for CsYbMnSe(3) are 1.60 and 1.59 eV, respectively; the optical band of the (010) crystal faces for CsYbZnS(3) and RbYbZnSe(3) are 2.61 and 2.07 eV, respectively.     

Tuning of optical band gaps: syntheses, structures, magnetic properties, and optical properties of CsLnZnSe(3) (Ln = Sm, Tb, Dy, Ho, Er, Tm, Yb, and Y)

Eight new quaternary selenides CsSmZnSe(3), CsTbZnSe(3), CsDyZnSe(3), CsHoZnSe(3,) CsErZnSe(3), CsTmZnSe(3), CsYbZnSe(3), and CsYZnSe(3) have been synthesized with the use of high-temperature solid-state experimental methods. These compounds are isostructural with KZrCuS(3), crystallizing with four formula units in the orthorhombic space group Cmcm. The structure of these CsLnZnSe(3) compounds is composed of [LnZnSe(3)(-)] layers separated by Cs atoms. The Ln atom is octahedrally coordinated by six Se atoms, the Zn atom is tetrahedrally coordinated by four Se atoms, and the Cs atom is coordinated by a bicapped trigonal prism of eight Se atoms. Because there are no Se-Se bonds in the structure, the oxidation state of Cs is 1+, that of Ln is 3+, and that of Zn is 2+. CsYbZnSe(3) exhibits an antiferromagnetic transition at 11 K, whereas CsSmZnSe(3) does not follow a Curie-Weiss law. The remaining rare-earth compounds are paramagnetic, and the calculated effective magnetic moments of the rare-earth ions agree well with their theoretical values. Optical absorption data on face-indexed single crystals of CsSmZnSe(3), CsErZnSe(3), CsYbZnSe(3), and CsYZnSe(3) demonstrate that the optical band gap changes by more than 0.75 eV with the composition and by as much as 0.20 eV with the crystal orientation. The optical band gaps range from 2.63 eV (CsSmZnSe(3), CsErZnSe(3)) to 1.93 eV (CsYbZnSe(3)) for the (010) crystal face and 2.56 eV (CsErZnSe(3)) to 1.88 eV (CsYbZnSe(3)) for the (001) crystal face. The difference in the optical band gap of the (010) face vs the (001) face varies from +0.05 eV (CsYbZnSe(3)) to +0.20 eV (CsSmZnSe(3)).     

SYNTHESIS AND CRYSTAL STRUCTURE OF 5, 10, 15, 20, 22, 24-HEXAHYDRO-5, 5, 10, 10, 15, 15, 20, 20-OCTAMETHYL-PORPHINE

<正> The title com pound (HHOMP) has been synthesized with the pho-toinduced condensation of acetone and pyrrole in the presence of iodoaromatic hydrocarbons, and its molecular and crystal structures have been determined by X-ray analysis. C28H36N4, Mr = 428. 63, triclinic; space group P1; a =10. 165(3), b = 10. 185(2), c=13. 012(3)(?); α=85. 41(2), β=67. 84(2), γ= 89. 75(2)°; V = 1243 (?)3; Z = 2; D = 1. 145g. cm-3; μ= 0. 635cm-1; F (000) = 464. Although the HHOMP molecule twists, it is found that the four nitrogen atoms are still in a plane.     

Syntheses, structure, some band gaps, and electronic structures of CsLnZnTe3 (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Y)

Eleven new quaternary rare-earth tellurides, CsLnZnTe3 (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Y), were prepared from solid-state reactions at 1123 K. These isostructural materials crystallize in the layered KZrCuS3 structure type in the orthorhombic space group Cmcm. The structure is composed of LnTe6 octahedra and ZnTe4 tetrahedra that share edges to form [LnZnTe3] layers. These layers stack perpendicular to [010] and are separated by layers of face- and edge-sharing CsTe8 bicapped trigonal prisms. There are no Te-Te bonds in the structure of these CsLnZnTe3 compounds so the formal oxidation states of Cs/Ln/Zn/Te are 1+/3+/2+/2-. Optical band gaps of 2.13 eV for CsGdZnTe3 and 2.12 eV for CsTbZnTe3 were deduced from single-crystal optical absorption measurements. A first-principles calculation of the density of states and the frequency-dependent optical properties was performed on CsGdZnTe3. The calculated band gap of 2.1 eV is in good agreement with the experimental value. A quadratic fit for the lanthanide contraction of the Ln-Te distance is superior to a linear one if the closed-shell atom is included.     

Araguspongines B, C, D, E, F, G, H, and J, new vasodilative bis-1-oxaquinolizidine alkaloids from an okinawan marine sponge, Xestospongia sp

Nine new vasodilative alkaloids, araguspongines A, B (1), C (2), D (3), E (4), F (5), G (6), H (7), and J (8), were isolated from an Okinawan marine sponge, Xestospongia sp. On the basis of chemical and physicochemical evidence, the absolute stereostructures of araguspongines B, D, E, F, G, H, and J were determined respectively as 1, 3, 4, 5, 6, 7, 8, and the relative stereostructure of araguspongine C was determined as 2 having two 1-oxaquinolizidine moieties. Araguspongines B, D, and E each comprised a pair of the enantiomers, 1a and 1b, 3a and 3b, and 4a and 4b, respectively.     

Synthesis, characterization, crystal structure, and electrochemical, photophysical, and protein-binding properties of luminescent rhenium(I) diimine indole complexes

We report the synthesis, characterization, and photophysical and electrochemical properties of a series of luminescent rhenium(I) diimine indole complexes, [Re(N-N)(CO)3(L)](CF3SO3) (N-N = 3,4,7,8-tetramethyl-1,10-phenanthroline (Me4-phen), L = N-(3-pyridoyl)tryptamine (py-3-CONHC2H4-indole) (1a), N-[N-(3-pyridoyl)-6-aminohexanoyl]tryptamine, (py-3-CONHC5H10CONHC2H4-indole) (1b); N-N = 1,10-phenanthroline (phen), L = py-3-CONHC2H4-indole (2a), py-3-CONHC5H10CONHC2H4-indole (2b); N-N = 2,9-dimethyl-1,10-phenanthroline (Me2-phen), L = py-3-CONHC2H4-indole (3a), py-3-CONHC5H10CONHC2H4-indole (3b); N-N = 4,7-diphenyl-1,10-phenanthroline (Ph2-phen), L = py-3-CONHC2H4-indole (4a), py-3-CONHC5H10CONHC2H4-indole (4b)), and their indole-free counterparts, [Re(N-N)(CO)3(py-3-CONH-Et)](CF3SO3) (py-3-CONH-Et = N-ethyl-(3-pyridyl)formamide; N-N = Me4-phen (1c), phen (2c), Me2-phen (3c), Ph2-phen (4c)). The X-ray crystal structure of complex 3a has also been investigated. Upon irradiation, most of the complexes exhibited triplet metal-to-ligand charge-transfer (3MLCT) (d pi(Re) --> pi*(diimine)) emission in fluid solutions at 298 K and in low-temperature glass. However, the structural features and long emission lifetimes of the Me4-phen complexes in solutions at room temperature suggest that the excited state of these complexes exhibited substantial triplet intraligand (3IL) (pi --> pi*) (Me4-phen) character. The binding interactions of these complexes to indole-binding proteins including bovine serum albumin and tryptophanase have been examined.     

The Synthesis of 12-Methyl-1, 2, 3, 4, 6, 7, 12, 12B-Octahydroindolo [2,3-A]Quinolizine (1), 1-Benzoyl-1, 2, 3, 4, 6, 7, 12, 12B-Octahydroindolo[2, 3-A]Quinolizine (2), and 1-Phenylcarbinol-1, 2, 3, 4, 6, 7, 12, 12B-Octahydroindolo[2, 3-A]Quinolizine (3)

12-Methyl-l, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo[2, 3-a]quinolizine (1) is synthesized through a new route developed in our laboratory. The most important step in this synthesis is the condensation of I-methyltryptophyl bromide (4) with 2-piperidone (5) to give N -(2-(1-methylidol)-3-ylethyl)-2-piperidone (6) in good yield (70%). The synthesis of 1-benzoyl-1, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo(2, 3-a]quinolizine (2) and 1-phenylcarbinol-1, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo[2, 3-a]quinolizine (3) follow the method developed by Wenkert. But the yield of tetrahydropyridine 9 from partial hydrogenation of pyridinum bromide 8 with 10% palladium-charcoal is 84% which is much higher than the best yield (40%) in the literature, since the phenyl group contribute additional stability.     

Syntheses, structures, and luminescence of novel lanthanide complexes of tripyridylamine, N,N,N',N'-tetra(2-pyridyl)-1,4-phenylenediamine and N,N,N',N'-tetra(2-pyridyl)biphenyl-4,4'-diamine

Two novel blue luminescent bridging ligands N,N,N',N'-tetra(2-pyridyl)-1,4-phenylenediamine (tppd) and N,N,N',N'-tetra(2-pyridyl)-1,1-biphenyl-4,4'-diamine (tpbpd) have been synthesized. Several novel lanthanide complexes containing 2,2',2"-tripyridylamine (2,2',2"-tpa), 2,2',3"-tpa, tppd, or tpbpd ligands have been synthesized and characterized structurally, which include Pr(hfa)3(2,2',2"-tpa), I, Ln(tmhd)3(2,2',3"-tpa), 2 (Ln = Dy, 2a; Eu, 2b; Tb, 2c; Sm, 2d), [Eu(tmhd)3][Pr(hfa)3](2,2',3"-tpa), 3, [Pr(hfa)3]2(tppd), 4, and [Ln(hfa)3]2(tpbpd), 5, where Ln = Pr (5a), Eu (5b), tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato, and hfa = hexafluoroacetylacetonate. The Dy(III), Eu(III), and Tb(III) complexes display a bright photoluminescence, which can be achieved by either a direct excitation process or an indirect excitation process. Compounds 2a-2d can be sublimed readily.     

Synthesis, characterisation, crystal structures, reactivity, and electrochemistry of ruthenium-nitrido, ruthenium-cobalt-imido and ruthenapyrrolidone carbonyl clusters containing alkyne ligands

Thermolysis of [Ru3(CO)9(mu3-NOMe)(mu3-eta2-PhC2Ph)] (1) with two equivalents of [Cp*Co(CO)2] in THF afforded four new clusters, brown [Ru5(CO)8(mu-CO)3(eta5-C5Me5)(mu5-N)(mu4-eta2-PhC2Ph)] (2), green [Ru3Co2(CO)7(mu3-CO)(eta5-C5Me5)2(mu3-NH)[mu4-eta8-C6H4-C(H)C(Ph)]] (3), orange [Ru3(CO)7(mu-eta6-C5Me4CH2)[mu-eta3-PhC2(Ph)C(O)N(OMe)]] (4) and pale yellow [Ru2(CO)6[mu-eta3-PhC2(Ph)C(O)N(OMe)]] (5). Cluster 2 is a pentaruthenium mu5-nitrido complex, in which the five metal atoms are arranged in a novel "spiked" square-planar metal skeleton with a quadruply bridging alkyne ligand. The mu5-nitrido N atom exhibits an unusually low frequency chemical shift in its 15N NMR spectrum. Cluster 3 contains a triangular Ru2Co-imido moiety linked to a ruthenium-cobaltocene through the mu4-eta8-C6H4C(H)C(Ph) ligand. Clusters 4 and 5 are both metallapyrrolidone complexes, in which interaction of diphenylacetylene with CO and the NOMe nitrene moiety were observed. In 4, one methyl group of the Cp* ring is activated and interacts with a ruthenium atom. The "distorted" Ru3Co butterfly nitrido complex [Ru3Co(CO)5(eta5-C5Me5)(mu4-N)(mu3-eta2-PhC2Ph)(mu-I)2I] (6) was isolated from the reaction of 1 with [Cp*Co(CO)I2] heated under reflux in THF, in which a Ru-Ru wing edge is missing. Two bridging and one terminal iodides were found to be placed along the two Ru-Ru wing edges and at a hinge Ru atom, respectively. The redox properties of the selected compounds in this study were investigated by using cyclic voltammetry and controlled potential coulometry. 15N magnetic resonance spectroscopy studies were also performed on these clusters.     

3,3,6,6-四甲基-9-邻氯苯基-1,8-二氧代-3,4,5,6,7,9-六氧化氧杂蒽的合成和晶体结构

标题化合物C23H25对O3Cl是由邻氯苯甲醛与5，5-二甲基1，3-环己二酮在N，N-二甲基甲酸腹中反应而得。结构通过单晶X-射线衍射法确定，其晶体属于单科晶系，空间群=1632。晶体结构用直接法解出，使用全矩阵最小二乘法对原子参数进行修正，最后的偏离因子为R=0．054，Rw一0．063。在晶体结构中，吡喃环与苯环之间的两面角为92．43°。     

General synthesis and structural evolution of a layered family of Ln8(OH)20Cl4 x nH2O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y)

The synthesis process and crystal structure evolution for a family of stoichiometric layered rare-earth hydroxides with general formula Ln(8)(OH)(20)Cl(4) x nH(2)O (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y; n approximately 6-7) are described. Synthesis was accomplished through homogeneous precipitation of LnCl(3) x xH(2)O with hexamethylenetetramine to yield a single-phase product for Sm-Er and Y. Some minor coexisting phases were observed for Nd(3+) and Tm(3+), indicating a size limit for this layered series. Light lanthanides (Nd, Sm, Eu) crystallized into rectangular platelets, whereas platelets of heavy lanthanides from Gd tended to be of quasi-hexagonal morphology. Rietveld profile analysis revealed that all phases were isostructural in an orthorhombic layered structure featuring a positively charged layer, [Ln(8)(OH)(20)(H(2)O)(n)](4+), and interlayer charge-balancing Cl(-) ions. In-plane lattice parameters a and b decreased nearly linearly with a decrease in the rare-earth cation size. The interlamellar distance, c, was almost constant (approximately 8.70 A) for rare-earth elements Nd(3+), Sm(3+), and Eu(3+), but it suddenly decreased to approximately 8.45 A for Tb(3+), Dy(3+), Ho(3+), and Er(3+), which can be ascribed to two different degrees of hydration. Nd(3+) typically adopted a phase with high hydration, whereas a low-hydration phase was preferred for Tb(3+), Dy(3+), Ho(3+), Er(3+), and Tm(3+). Sm(3+), Eu(3+), and Gd(3+) samples were sensitive to humidity conditions because high- and low-hydration phases were interconvertible at a critical humidity of 10%, 20%, and 50%, respectively, as supported by both X-ray diffraction and gravimetry as a function of the relative humidity. In the phase conversion process, interlayer expansion or contraction of approximately 0.2 A also occurred as a possible consequence of absorption/desorption of H(2)O molecules. The hydration difference was also evidenced by refinement results. The number of coordinated water molecules per formula weight, n, changed from 6.6 for the high-hydration Gd sample to 6.0 for the low-hydration Gd sample. Also, the hydration number usually decreased with increasing atomic number; e.g., n = 7.4, 6.3, 7.2, and 6.6 for high-hydration Nd, Sm, Eu, and Gd, and n = 6.0, 5.8, 5.6, 5.4, and 4.9 for low-hydration Gd, Tb, Dy, Ho, and Er. The variation in the average Ln-O bond length with decreasing size of the lanthanide ions is also discussed. This family of layered lanthanide compounds highlights a novel chemistry of interplay between crystal structure stability and coordination geometry with water molecules.     

A Novel Fused Phosphorus Heterocycle: 4-(1'''',2'''',3'''',4-Tetrahydro-1, 3, 2-benzodiazaphosphorin-2''''-sulfide)-3, 4b, 4a-thiazphosphaphenanthridine Derivative

Organophosphorus compounds are ubiquitous in nature and they have broad applications in the fields of agriculture and medicine1-4. There has been a considerably growing interest in heterocyclic compounds due to their pharmaceutical importance and extensive application in organic synthesis, and the application of heterocycles is suggested to enhance the biological activity and/or offer other diverse properties5-7. In the previous work8, we have reported that 11-ethoxycarbonylmethyl-6-oxo-3, 4…     

Carboxyketenes, methyleneketenes, vinylketenes, oxetanediones, ynols, and ylidic ketenes from Meldrum's acid derivatives

It has been documented that 5-methylene-Meldrum's acid derivatives (1, 12 ) and their enols (2, 13) can undergo fragmentation to malonic anhydrides (4, 19 ), carboxyketenes (3, 16) and methyleneketene (5, 21 , 35 ), as well as cyclization to pyrrole-3-one and thiophene-3-one derivatives 11a,b (but not furan-3-ones 11c ) under the conditions of flash vacuum thermolysis (FVT). Here we report theoretical calculations at the B3LYP/6-311 + G(2d, p) and G3X(MP2) levels of theory, which allow a rationalization of these observations. The calculated activation barriers for these reactions are all of the order of 37-40 kcal mol(-1). Hydroxyacetylenes (alkynols) 7 are sometimes observed in FVT reactions of Meldrum's acid derivatives. Their formation is now explained as an FVT reaction of the carboxyketenes (e.g. 3-->7 and 32-->34) with a calculated activation barrier of ca. 39 kcal mol(-1). The cyclization of alkylamino- and alkylthio-substituted methyleneketenes 8a,b to pyrrolone and thiophenone derivatives 11a,b is found to be energetically very feasible under FVT conditions, and even in some cases in solution, with activation barriers of 33-39 kcal mol(-1). This cyclization takes place via the fleeting ylidic ketene intermediates 9a,b,25, and 37a,b, which exist in very shallow energy minima. Alkoxy-substituted methyleneketenes 8c do not cyclize in this manner due to the rather high, but in principle not impossible, activation barriers for the initial 1,4-H shifts to the ylidic ketenes 9c (ca. 47 kcal mol(-1)).     

Evolution of the crystal structure of RVO3 (R = La, Ce, Pr, Nd, Tb, Ho, Er, Tm, Yb, Lu, Y) perovskites from neutron powder diffraction data

RVO3 perovskites have been prepared in the widest range of R (3+) ionic size, from LaVO3 to LuVO3. Pure polycrystalline samples have been obtained by a citrate technique leading to reactive RVO4 precursors, followed by thermal treatments in a reducing H2/N2 (15/85%) flow to stabilize V(3+) cations. These oxides have been studied at room temperature by high-resolution neutron powder diffraction to follow the evolution of the crystal structures along the series. The distortion of the orthorhombic perovskite (space group Pbnm), characterized by the tilting angle of the VO6 octahedra, progressively increases from La to Lu due to simple steric factors. Additionally, all of the perovskites show a subtle distortion of the VO6 octahedra which significantly increases from La to Tb, and then slightly decreases for the last terms of the series. The stability of the crystal structure is also discussed in light of bond-valence arguments.     

Rhodium-103 NMR of [Rh(X)(PPh3)3] [X = Cl, N3, NCO, NCS, N(CN)2, NCBPh3, CNBPh3, CN] and derivatives containing CO, isocyanide, pyridine, H2 and O2. Ligand, solvent and temperature effects

Rhodium-103 chemical shifts are reported for 62 compounds, namely [Rh(X)(PPh3)3] [X = Cl, N3, NCO, NCS, N(CN)2, NCBPh3, CNBPh3, CN] and derivatives formed by replacement of a phosphine by CO, xylyl isocyanide (XNC) and pyridine and/or by oxidative addition of H2 or O2 to give trans-[Rh(X)(PPh3)2(CO)] (delta in the range -816 to -368 ppm) trans-[Rh(X)(PPh3)2(XNC)] (delta -817 to -250 ppm), cis-[Rh(X)(PPh3)2(py)] (the trans isomer is formed with X = CN, CNBPh3) (delta -233 to 170 ppm), [Rh(X)(H)2(PPh3)3] (delta -611 to 119), trans-[Rh(X)(H)2(PPh3)2(py)] (delta -30 to 566 ppm), [Rh(X)(O2)(PPh3)3] (delta 1393 to 3273 ppm) and cis-[Rh(X)(O2)(PPh3)2(py)] (delta 1949 to 3374 ppm). For the majority of these compounds data were obtained from solutions in chloroform and in toluene at temperatures of 247 and 300 K; for [Rh(X)(PPh3)3] (delta -562 to -4 ppm) data are reported at a number of temperatures in the range 195-300 K for solutions in chloroform, toluene and dichloromethane and at 300 K for solutions in DMSO. The expected trend to lower delta(103Rh) with decreasing temperature (vibrational shielding) is observed for the dichloromethane data, but data from solutions {of [Rh(X)(PPh3)3]} in chloroform and toluene show a number of features which diverge from this pattern, i.e. shifts to higher delta are found to accompany a decrease in temperature, most noticeably where X = CN and Cl [on changing the solvent from dichloromethane to chloroform changes in delta(103Rh) of up to 172 ppm are observed]. These results are interpreted in terms of a hydrogen-bonded interaction with the solvent that is enhanced by the presence of a polarizable ligand (CN, Cl). With a ligand (O2CCF3) that is only weakly polarizable the solvent dependence of delta(103Rh) is minimal.     

微波辐射下4-(4-羟基-3-甲氧基)苯基-3,3,6,6-四甲基-1,8-二氧代1,2,3,4,5,6,7,8,9,10-十氢吖啶的合成和晶体结构

标题化合物C24H29NO4?1/2C2H5OH稨2O)由香兰素、5,5-二甲基-1,3-环己二酮、醋酸铵在微波辐射下干反应并经95%乙醇重结晶而得C24H29NO4穀2(C2H5OH稨2O)晶体。结构通过单晶X-射线衍射法确定,其晶体属单斜晶系,空间群P21/n, a = 9.810(2), b = 14.516(3), c = 17.008(3) ? b = 101.03(2), V = 2377.2(8) ?, Z = 4, Mr = 427.52, Dc = 1.195 g/cm3 , m(MoKa) = 0.082 mm-1, F(000) = 920。晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R = 0.0406, wR = 0.0892。X-射线衍射分析结果表明,吡啶环和与之稠合的2个六员环均为信封式构象。     

Alkylthio bridged 44 cve triangular platinum clusters: synthesis, oxidation, degradation, ligand substitution, and quantum chemical calculations

Acetylplatinum(II) complexes trans-[Pt(COMe)Cl(L)2] (L = PPh3, 2a; P(4-FC6H4)3, 2b) were found to react with dialkyldisulfides R2S2 (R = Me, Et, Pr, Bu; Pr = n-propyl, Bu = n-butyl), yielding trinuclear 44 cve (cluster valence electrons) platinum clusters [(PtL)3(mu-SR)3]Cl (4). The analogous reaction of 2a-b with Ph2S2 gave SPh bridged dinuclear complexes trans-[{PtCl(L)}2(mu-SPh)2] (5), whereas the addition of Bn2S2 (Bn = benzyl) to 2a ended up in the formation of [{Pt(PPh3)}3(mu3-S)(mu-SBn)3]Cl (6). Theoretical studies based on the AIM theory revealed that type 4 complexes must be regarded as triangular platinum clusters with Pt-Pt bonds whereas complex 6 must be treated as a sulfur capped 48 ve (valence electrons) trinuclear platinum(II) complex without Pt-Pt bonding interactions. Phosphine ligands with a lower donor capability in clusters 4 proved to be subject to substitution by stronger donating monodentate phosphine ligands (L' = PMePh2, PMe2Ph, PBu3) yielding clusters [(PtL')3(mu-SR)3]Cl (9). In case of the reaction of clusters 4 and 9 with PPh2CH2PPh2 (dppm), a fragmentation reaction occurred, and the complexes [(PtL)2(mu-SMe)(mu-dppm)]Cl (12) and [Pt(mu-SMe)2(dppm)] (13) were isolated. Furthermore, oxidation reactions of cluster [{Pt(PPh3)}3(mu-SMe)3]Cl (4a) using halogens (Br2, I2) gave dimeric platinum(II) complexes cis-[{PtX(PPh3)}2(mu-SMe)2] (14, X = Br, I) whereas oxidation reactions using sulfur and selenium afforded chalcogen capped trinuclear 48 ve complexes [{Pt(PPh3)}3(mu3-E)(mu-SMe)3] (15, E = S, Se). All compounds were fully characterized by means of NMR and IR spectroscopy, microanalyses, and ESI mass spectrometry. Furthermore, X-ray diffraction analyses were performed for the triangular cluster 4a, the trinuclear complex 6, as well as for the dinuclear complexes trans-[{Pt(AsPh3)}2(mu-SPh)2] (5c), [{Pt(PPh3)}2(mu-SMe)(mu-dppm)]Cl (12a), and [{{PtBr(PPh3)}2(mu-SMe)2] (14a).     

Thermochemical database of Halomethanes, Halosilanes, Halophosphines, and Haloamines

An accurate thermochemical database for 28 halides of carbon, silicon, nitrogen, and phosphorus is presented. The database provides improved standard enthalpies of formation for several compounds of ecological importance (CH3F, CF2Cl2, CFCl3) together with enthalpies of other compounds which are not known due to experimental difficulties in measuring their enthalpies. We also present a comparison of the latest ab initio methods (CBS-QB3 and G3) which are used for thermochemical predictions. The comparison shows that the G3 method consistently underestimates delta H degree f by 1-2 kJ/mol (relative to CBS-QB3).     

Crystal structures and magnetic properties of mixed iridium-ruthenium triple perovskites. 2. Ba3MRuIrO9 (M=Li, Na, Mg, Ni, Zn, Bi, In)

Crystal structures and magnetic properties of polycrystalline Ba3MRuIrO9 (M1+=Li, Na; M2+=Mg, Ni, Zn; M3+=Bi, In) were investigated. Rietveld refinements of the crystal structures using powder diffraction data indicate that, with the exception of Ba3BiRuIrO9, all compounds crystallize in the 6H-BaTiO3 structure type in space group P63/mmc; Ba3BiRuIrO9 crystallizes in space group C2/c. The 6H-BaTiO3, or triple-perovskite, structure is composed of hexagonal and cubic stacking of [AO3] layers and contains face- and corner-sharing octahedra. The structures in this study contain a disordered mixture of Ir and Ru in the face-sharing octahedra dimers, which are connected via corner-shared MO6 octahedra. Magnetic susceptibility measurements as a function of temperature were carried out on each compound. Effective magnetic moments were smaller than values estimated using spin-only moments, which indicate the presence of spin-orbit coupling and strong interactions in the face-sharing octahedra that contain a disordered mixture of Ru and Ir on a single crystallographic site. Over a broad temperature range, a divergence of the zero-field-cooled and field-cooled data were observed for Ba3MgRuIrO9, Ba3NiRuIrO9, Ba3ZnRuIrO9, and Ba3LiRuIrO9.