Insertion of Ethyl Isocyanate at the Tungsten–Chlorine Bond. Crystal Structure of 1,3,5-Triethyl-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione

The reaction of tungsten hexachloride with excess ethyl isocyanate in dichloroethane leads to the insertion of three ligand molecules at one of the tungsten–chlorine bonds. The data of elemental analysis and IR spectroscopy confirm that the thermolysis of the reaction mixture affords the WCl₄(L₃Cl) complex (I), where L = –N(Et)C(O)–. The structure of the chain of inserted molecules in I is established on the basis of IR and NMR data, and the results of X-ray diffraction analysis of crystals of an organic product (II) of the hydrolysis of I. According to the latter, compound (II) is a derivative of s-triazine—1,3,5-triethyl-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.     

Dimethylhydroxyoxosulfonium(VI) Hexafluoridometallates, [(CH3)2SO(OX)]+[MF6]–(X = H,D; M = As,Sb)

Dimethylsulfone reacts in the binary superacidic systems XF/MF₅ (X = H, D; M = As, Sb) under the formation of the corresponding salts of the type [(CH₃)₂SO(OX)]⁺[MF₆]^–. The salts are characterized by low temperature vibrational spectroscopy. In case of [(CH₃)₂SO(OH)]⁺[SbF₆]^– a single‐crystal X‐ray structure analysis is reported. The salt crystallizes in the orthorhombic space group Pbca with eight formula units per unit cell [a = 10.3281(3) Å, b = 12.2111(4) Å, c = 13.9593(4) Å]. The experimental results are discussed together with quantum chemical calculations on the PBE1PBE/6‐311G++(3pd,3df) level of theory.     

Synthesis of 8,10-dimethyl-1,10b-dihydro[1,3,5]triazino-[2,1-a]isoindole-2,4,6(3H)-trione by Direct arylation of 1,3,5-triazine-2,4(1H,3H)-dione

Direct arylation of 1,3,5-triazine-2,4(1H,3H)-dione with mesitylene afforded a novel fused heterocyclic system, 8,10-dimethyl-1,10b-dihydro[1,3,5]triazino[2,1-a]isoindole-2,4,6(3H)-trione.     

Structural/bonding insights from new geometrical varieties of two Pt-Au carbonyl/phosphine clusters, [Pt3(AuPPh3)5(mu2-CO)2L3]+ (L3 = (CO)2PPh3) and [(mu6-Au){Pt3(mu2-CO)3L4}2]+ (L = PMe3)

Structural/bonding considerations of two new Pt-Au clusters, [Pt3(AuPPh3)5(mu2-CO)2(CO)2PPh3]+ (1) and [(mu6-Au){Pt3(mu2-CO)3(PMe3)4}2]+ (2) isolated (as chloride salts), revealed: (i) that the heretofore unknown 20-electron Pt-centered Pt2Au5 icosahedral cage fragment (five missing vertices) of is best viewed as a 44-electron triangular Pt3 adduct of a nearly planar 39-electron [Pt3(mu2-CO)2L3]+ (L3 = (CO)2PPh3) and five one-electron donating AuPPh3 ligands; and (ii) that the geometrically distorted trimethylphosphine "full" Pt3AuPt3 sandwich of is the first example of two nucleophilic 44-electron triangular Pt3(mu2-CO)3L4 (3 : 3 : 4) units (L = PMe3) which asymmetrically encapsulate a central electrophilic Au(I).     

Diruthenium complexes [((acac)2RuIII)2(mu-OC2H5)2], [((acac)(2RuIII)2(mu-L)](ClO4)2, and [((bpy)(2RuII)2(mu-L)](ClO4)4 [L = (NC5H4)2-N-C6H4-N-(NC5H4)2, acac = acetylacetonate, and bpy = 2,2'-bipyridine]. synthesis, structure, magnetic, spectral, and photophysical aspects

Paramagnetic diruthenium(III) complexes (acac)(2)Ru(III)(mu-OC(2)H(5))(2)Ru(III)(acac)(2) (6) and [(acac)(2)Ru(III)(mu-L)Ru(III)(acac)(2)](ClO(4))(2), [7](ClO(4))(2), were obtained via the reaction of binucleating bridging ligand, N,N,N',N'-tetra(2-pyridyl)-1,4-phenylenediamine [(NC(5)H(4))(2)-N-C(6)H(4)-N-(NC(5)H(4))(2), L] with the monomeric metal precursor unit (acac)(2)Ru(II)(CH(3)CN)(2) in ethanol under aerobic conditions. However, the reaction of L with the metal fragment Ru(II)(bpy)(2)(EtOH)(2)(2+) resulted in the corresponding [(bpy)(2)Ru(II) (mu-L) Ru(II)(bpy)(2)](ClO(4))(4), [8](ClO(4))(4). Crystal structures of L and 6 show that, in each case, the asymmetric unit consists of two independent half-molecules. The Ru-Ru distances in the two crystallographically independent molecules (F and G) of 6 are found to be 2.6448(8) and 2.6515(8) A, respectively. Variable-temperature magnetic studies suggest that the ruthenium(III) centers in 6 and [7](ClO(4))(2) are very weakly antiferromagnetically coupled, having J = -0.45 and -0.63 cm(-)(1), respectively. The g value calculated for 6 by using the van Vleck equation turned out to be only 1.11, whereas for [7](ClO(4))(2), the g value is 2.4, as expected for paramagnetic Ru(III) complexes. The paramagnetic complexes 6 and [7](2+) exhibit rhombic EPR spectra at 77 K in CHCl(3) (g(1) = 2.420, g(2) = 2.192, g(3) = 1.710 for 6 and g(1) = 2.385, g(2) = 2.177, g(3) = 1.753 for [7](2+)). This indicates that 6 must have an intermolecular magnetic interaction, in fact, an antiferromagnetic interaction, along at least one of the crystal axes. This conclusion was supported by ZINDO/1-level calculations. The complexes 6, [7](2+), and [8](4+) display closely spaced Ru(III)/Ru(II) couples with 70, 110, and 80 mV separations in potentials between the successive couples, respectively, implying weak intermetallic electrochemical coupling in their mixed-valent states. The electrochemical stability of the Ru(II) state follows the order: [7](2+) < 6 < [8](4+). The bipyridine derivative [8](4+) exhibits a strong luminescence [quantum yield (phi) = 0.18] at 600 nm in EtOH/MeOH (4:1) glass (at 77 K), with an estimated excited-state lifetime of approximately 10 micros.     

Synthesis of 3,5-disubstituted 1-amino-1,3,5-triazine-2,4,6-triones (or 1-aminocyanurates) by cyclic transformation of 1,3,4-oxadiazol-2(3H)-one derivatives

The 5-aryl(or methyl)-3-phenylcarbamoyl-1,3,4-oxadiazol-2(3H)-ones 2 , in the presence of sodium hydride in anhydrous dimethylformamide, were transformed into 1-benzamido(or acetamido)-3,5-diphenyl-1,3,5-triazine-2,4,6-trione derivatives 7 in poor yields. However, compounds 7 were obtained in better yields when the sodium salts of 5-aryl(or methyl)-1,3,4-oxadiazol-2(3H)-ones 1 were treated with two equivalents of aryl(or ethyl)isocyanates. Acidic hydrolysis of 1-acetamido-3,5-diphenyl-1,3,5-triazine-2,4,6-trione ( 7i ) provided the corresponding free N-amino derivative 9 . Nitrous deamination of 9 gave the known 3,5-diphenyl-1,3,5-triazine-2,4,6-trione ( 11 ). This cyclic transformation is the first one to be reported providing 1,3,5-triazine-2,4,6-trione derivatives.     

Isovalent and mixed-valent diruthenium complexes [(acac)2RuII (-bpytz)RuII(acac)2] and [(acac)2RuII(-bpytz)RuIII(acac)2](ClO4) (acac = acetylacetonate and bpytz = 3,6-bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine): synthesis, spectroelectrochemical, and epr investigation

The title compounds involving the structurally characterized bridging ligand bpytz were characterized, showing very strong electrochemical stabilization of the mixed-valent RuIIRuIII state (Kc = 10(13.9)) but no detectable (epsilon < 20 M(-1) cm(-1)) intervalence charge-transfer band in the infrared region. In situ reduction of the neutral precursor produces a diruthenium(II) complex of the bpytz radical anion according to EPR spectroscopy, whereas oxidation of the mixed-valent form leads to a diruthenium(III) species.     

Übergangsmetallsubstituierte Gallane: Synthese,Struktur und Bindungsverhältnisse von [(CO)4CoGaEt2(NC7H13)], [(PMe3)(CO)3CoGaCl2(NMe3)], [(CO)4CoGaCl3]K und [(CO)5MnGaEt2(NC7H13)]

Transition Metal substituted Gallanes: Synthesis and X-Ray Structures of [(CO)₄CoGaEt₂(NC₇H₁₃)], [(PMe₃)(CO)₃CoGaCl₂(NMe₃)], [(CO)₄CoGaCl₃]K, and [(CO)₅MnGaEt₂(NC₇H₁₃)] The transition metal substituted gallanes [(CO)₅MnGaEt₂(NC₇H₁₃)] ( 1 ), [(PMe₃)(CO)₃CoGaCl₂ · (NMe₃)] ( 2 ), [(CO)₄CoGaEt₂(NC₇H₁₃)] ( 3 ), and [(CO)₄CoGaCl₃]K ( 4 ) were obtained by the reaction of the potassium/sodium salts of the manganese- and cobaltcarbonylmetallates with the chlorogallium species ClGaEt₂(NC₇H₁₃), Cl₃Ga(NMe₃), and GaCl₃. The structures were established by single crystal X-ray analysis 1 : space group P2₁/c (I.T.-No.: 14); Z = 4; a = 1425.4(2) pm, b = 1007.4(1) pm, c = 1429.9(3) pm; β = 113.92(1)°; 2 : space group P2₁/m (I.T.-No.: 11); Z = 2; a = 746.1(1) pm, b = 1131.2(1) pm, c = 1061.5(1) pm; β = 101.87(1)°; 3 : space group P2₁/c (I.T.-No.: 14); Z = 8; a = 1405.9(2) pm, b = 1786.2(2) pm, c = 1430.9(2) pm; β = 91.47(1)°; 4 : space group P2₁/c; Z = 4; a = 1185.7(1) pm, b = 895.4(1) pm, c = 1144.7(3) pm; β = 106.47(2)°. The model compounds [{L′(CO)₃Co}GaX₂L] (L′ = CO, PH₃; L = NH₃, X = H, Cl) with polar σ(Co–Ga) bonds and the effect of the substituent on the bond length are characterized with DFT-calculations.     

Syntheses and magnetic properties of hexanuclear [Cp2Mn3(L1)4]2 and octanuclear [Mn8(L2)12(mu 4-O)2] (L1 = 2-HNC5H5N,L2 = 2-NH-3-Br-5-MeC5H3N,Cp = C5H5)

The reactions of manganocene, Cp2Mn, with 2-aminopyridine (L1H) or 2-amino-3-bromo-5-methylpyridine (L2H) give the novel hexanuclear and octanuclear Mn(II) amido cage compounds [Cp2Mn3(L1)4]2 (1) and [Mn8(L2)12(mu 4-O)2] (2); magnetic measurements on which provide a rare insight into the magnetic properties of amido-bridged metal clusters.     

Preparation and characterization of copper sulfide nanoparticles from symmetrical [(Bu)2NC(S)NC(O)C6H3(3,5-NO2)2]2Cu(II) and [(Bu)2NC(S)NC(O)C6H4(4-NO2)]2Cu(II) complexes by thermolysis

Trigonal copper sulfide nanoparticles were synthesized from symmetrical [(Bu)₂NC(S)NC(O)C₆H₃(3,5-NO₂)₂]₂Cu(II) and [(Bu)₂NC(S)NC(O)C₆H₄(4-NO₂)]₂Cu(II) complexes by thermolysis in the presence of surfactant oleylamine. The symmetrical copper complexes were synthesized by reaction of copper(II) acetate with N-(3,5-dinitrobenzoyl)-N′,N′-dibutylthiourea and N-(4-nitrobenzoyl)-N′,N′-dibutylthiourea. The symmetrical copper complexes were characterized by FT-IR spectroscopy, elemental analysis, and mass spectrometry (MS-APCI). The single-crystal X-ray structure of [(Bu)₂NC(S)NC(O)C₆H₄(4-NO₂)]₂Cu(II) has been determined from single-crystal X-ray diffraction data. These metal complexes have been used as single source precursors for the preparation of copper sulfide nanoparticles. The deposited copper sulfide nanoparticles were characterized by X-ray powder diffraction and transmission electron microscopy.     

(1,3,5-C3P3H3)M与(1,3,5-C3P3H3)2M (M=Ti,V, Cr)配合物的结构与芳香性

运用密度泛函理论研究了(1,3,5-C3P3H3)M和(1,3,5-C3P3H3)2M (M=Ti,V,Cr)的结构、键合能以及芳香性.结果表明:低自旋的(1,3,5-C3P3H3)M和(1,3,5-C3P3H3)2M基态结构分别具有C3v和D3h对称性.金属与配体间为共价作用,二者之间存在σ、π和σ三种成键方式.V的三明治配合物的解离方式与Ti和Cr的三明治配合物不同,前者为分步解离,后两者则为一步解离.其中(1,3,5-C3P3H3)2Cr(D3h)的第一解离能最大,配合物最稳定.这些三明治和半三明治配合物都具有中心芳香性、内芳香性和外芳香性,且中心芳香性均大于自由配体(1,3,5-C3P3H3)的中心芳香性,芳香性主要贡献来源于π键和金属原子的孤对电子.内芳香性按照Ti、V、Cr的顺序依次增大,且内芳香性明显要大于外芳香性.高自旋的半三明治(1,3,5-C3P3H3)Ti(C3,5A1)与单重态(1,3,5-C3P3H3)Ti (C3v,1A1)相比,配体的变形性增大,稳定性增加,且C平面中心芳香性和内芳香性均增大,但P平面的中心芳香性却降低.     

新颖双核钐硫酚化合物[(THF)3I2Sm(m-SAr)]2 (Ar = Ph, 4-Me2NC6H4)的合成与化合物[(THF)3I2Sm(m-S-4-Me2NC6H4)]2的晶体结构

Reactions of SmI2 in THF with ArSSAr produced two binuclear samarium thiolate complexes [（THF）3I2- Sm（μ-SAr）]2 [Ar=Ph （1）, 4-Me2NC6H4 （2）] in high yields. The structure of 2 was characterized by single crystal X-ray crystallography. The crystal of 2 belongs to the triclinic system with space group P 1 and a=0.95705（13） nm, b= 1.22287（14） nm, c= 1.26450（14） nm, a=64.194（11）°, B=78.491（13）°, y=76.176（12）°, V= 1.2860（3） nm^3, Z= 1,μ=4.783 mm^-1, Dc= 1.964 Mg/m^3, M= 1521.19, S= 1.046, R1=0.0358, wR2=0.0910. X-ray analysis revealed that 2 is a thiolate-bridged dimer in which each Sm atom adopts a distorted pentagonal bipyramidal coordi- nation geometry.     

N,N'-diisopropyl-N'-bis(trimethylsilyl)guanidinate ligand as a supporting coordination environment in yttrium chemistry. Synthesis, structure, and properties of complexes [(Me(3)Si)(2)NC(Ni-Pr)(2)]YCl(2)(THF)(2), [(Me(3)Si)(2)NC(Ni-Pr)(2)]Y(CH(2)SiMe(3))(2)(THF)(2), and [(Me(3)Si)(2)NC(Ni-Pr)(2)]Y[(mu-H)(mu-Et)(2)BEt](2)(THF)

The reaction of anhydrous YCl3 with an equimolar amount of lithium N,N'-diisopropyl-N' '-bis(trimethylsilyl)guanidinate, Li[(Me3Si)2NC(Ni-Pr)2], in tetrahydrofuran (THF) afforded the monomeric monoguanidinate dichloro complex {(Me3Si)2NC(Ni-Pr)2}YCl2(THF)2 (1). Alkylation of complex 1 with 2 equiv of LiCH2SiMe3 in hexane at 0 degrees C yielded the monomeric salt-free dialkyl complex {(Me3Si)2NC(Ni-Pr)2}Y(CH2SiMe3)2(THF)2 (2). The bis(triethylborohydride) complex [(Me3Si)2NC(Ni-Pr)2]Y[(mu-H)(mu-Et)2BEt]2(THF) (5) was prepared by the reaction of complex 1 with 2 equiv of LiBEt3H in a toluene-THF mixture at 0 degrees C. The complexes 1, 2, and 5 were structurally characterized. Complex 2 as well as the systems 2-Ph3B, 2-Ph3B-MAO, and 1-MAO (MAO = methylaluminoxanes) in toluene were inactive in ethylene polymerization, while the product obtained in situ from the reaction of complex 2 with a 2-fold molar excess of PhSiH3 in toluene polymerized ethylene with moderate activity.     

A molecular pinwheel multicopper(I) cluster, [(L(S-))6Cu(I)13(S2-)2]3+ with mu4-sulfido, mu3-thiolato and nitrogen ligands

A copper(I) complex with new N2S thiol ligand transforms to a multicopper(I) cluster, [(L(S-))6Cu(I)13(S2-)2]3+ (1); its X-ray structure exhibiting mu4-sulfido and mu3-thiolato coordination is presented and compared to other cuprous thiolato/sulfido clusters including that observed in the copper enzyme nitrous oxide reductase.     

The metal-NO interaction in the redox systems [Cl5Os(NO)]n-, n = 1-3, and cis-[(bpy)2ClOs(NO)]2+/+: calculations, structural, electrochemical, and spectroscopic results

Experimental and computational results for the two-step redox system [Cl5Os(NO)]n- (n = 1-3) are reported and discussed in comparison to the related one-step redox systems [Cl5Ru(NO)]n- and [Cl5Ir(NO)]n- (n = 1, 2). The osmium system exhibits remarkably low oxidation and reduction potentials. The structure of the precursor (PPh4)2[Cl5Os(NO)] is established as an {MNO}6 species with almost linear OsNO arrangement at 178.1 degrees. Density-functional theory (DFT) calculations confirm this result, and a comparison of structures calculated for several oxidation states reveals an increased labilization of the trans-positioned M-Cl bond on reduction in the order M = Ir < Os < Ru. Accordingly, the intact reduced form [Cl5Os(NO)]3- could not be observed in fluid solution even on electrolysis at -70 degrees C in n-butyronitrile solution, as confirmed both by DFT calculations and by comparison with the electron paramagnetic resonance and infrared spectroelectrochemically characterized redox pairs cis-[(bpy)2ClOs(NO)]2+/+ and [(CN)5Os(NO)]2-/3-. The DFT calculations indicate that the oxidation of [Cl5Os(NO)]2- occurs largely on the metal, the highest occupied molecular orbital (HOMO) of the precursor being composed of Os 5d (58%) and Cl(eq) 3p orbitals (41%). As for the related [(CN)5Os(NO)]2-, the reduction is largely NO centered, the lowest unoccupied molecular orbital (LUMO) of [Cl5Os(NO)]2- has 61% pi*(NO) character with significant 5d Os contributions (34%). A rather large degree of metal-NO back-donation is estimated to occur in the {OsNO}7 configuration of [Cl5Os(NO)]3- which leads to an unusual low value of 1513 cm(-1) calculated for nu(NO), signifying contributions from an Os(III)(NO-) formulation. Detailed analyses of the conformational dependence of the g anisotropy suggest that the different reduced species reported previously for [Cl5Os(NO)]3- in AgCl host lattices may be distinct in terms of eclipsed or staggered conformations of the bent NO. axial ligand relative to the Os(II)Cl4 equatorial plane. The staggered form is calculated to be more stable by 105 cm(-1). The weak absorptions of [Cl5Os(NO)]2- at 573, 495, and 437 nm are assigned as MLCT/LLCT transitions to the doubly degenerate pi*(NO) LUMO. The oxidized form [Cl5Os(NO)]- contains Os(III) in an {OsNO}5 configuration with a spin density of 0.711 on Os. In all three states of [Cl5Os(NO)]n-, the N bonded form is vastly preferred over the NO-side-on bonded alternative.