7-Deazapurines: Synthesis of new pyrrolo[2,3-d]pyrimidin-4-ones catalyzed by a Brønsted-acid ionic liquid as a green and reusable catalyst

Some new 2-aryl-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-ones have been prepared through cyclocondensation of 2-amino-1H-pyrrole-3-carboxamides with aromatic aldehydes followed by air oxidation in the presence of 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate [(CH2)4SO3HMIM][HSO4], a Brønsted-acidic ionic liquid (IL), as a green and reusable catalyst in solvent-free conditions.     

过渡金属甲基磺酸盐催化醇的四氢吡喃化反应

以过渡金属甲基磺酸盐［Mn(CH₃SO₃)₂·2H₂O, Cu(CH₃SO₃)₂·4H₂O, Co(CH₃SO₃)₂·4H₂O和Zn(CH₃SO₃)₂·4H₂O］为催化剂,在室温条件下催化醇的四氢吡喃化反应,并对反应条件进行了优化。结果表明：当醇用量为30 mmol,醇和3,4-二氢吡喃摩尔比为1.0 ：1.1,甲基磺酸盐用量为1 mmol,二氯甲烷20 mL时,可高效催化醇的四氢吡喃化反应。与路易斯酸催化活性相比,过渡金属甲基磺酸盐催化醇的四氢吡喃化反应效果最好,催化酚的效果较差。用Mn(CH₃SO₃)₂·2H₂O和Cu(CH₃SO₃)₂·4H₂O催化正丁醇的四氢吡喃化反应,重复使用5次,收率分别为89%和92%。     

Synthesis and Biological Evaluation of Some Novel N,N ′-Bis-(1,2,4-Triazin-4-Yl)Dicarboxylic Acid Amides and Some Fused Rings with 1,2,4-Triazine Ring

Some of novel N , N '-bis-(1,2,4-triazin-4-yl)dicarboxylic acid amides ( 2-5 ) and thiadiazolo[2,3- b ][1,2,4]triazin-7-yl carboxylic acid derivatives ( 6 , 7 ) were prepared by heating 4-amino-6-methyl-5-oxo-3-thioxo-2,3,4,5-tetrahydro-1,2,4-triazine ( 1 ) with different dicarboxylic acids (oxalic, malonic, fumaric, maleic, succinic, and phthalic acids respectively) in POCl 3 . Refluxing 1 with 1-chloro-2,4-dinitrobenzene in DMF yielded 3-methyl-6-nitro-10 H -benzo[1,2,4]thiadiazino[2,3- c ][1,2,4]triazin-4-one ( 8 ). Condensation of 1 with 2,4-pentandione in refluxing acetic acid furnished 6-methyl-4-(1-methyl-3-oxobut-1-enylamino)-3-thioxo-3,4-dihydro-2 H -[1,2,4]triazin-5-one ( 9 ). 3,8-D imethyl[1,2,4] triazino[3,4- b ][1,3,4]thiadiazine-4,7-dione ( 11 ) was prepared by refluxing 1 with 2-bromopropionyl bromide in anhydrous benzene to afford the corresponding N -acetylated derivative 10 , which was cyclized by using triethylamine. Also, some triazinylquinazolinones 13a , b were obtained by fusion of 1 with 6-bromo(and/or 6,8-dibromo)-2-methyl-3,1-benzoxazin-4 H -ones.     

Reactions of tris(amino)phosphines with arylsulfonyl azides: product dependency on tris(amino)phosphine structure

The Staudinger reaction of N(CH2CH2NR)3P [R = Me (1), Pr (2)] with 1 equiv of N3SO2C6H4Me-4 gave the ionic phosphazides [N(CH2CH2NR)3PN][SO2C6H4Me-4] [R = Me (3), R = Pr (5a)], and the same reaction of 2 with N3SO2C6H2Me3-2,4,6 gave the corresponding aryl sulfinite 5b. On the other hand, the reaction of 1 with 0.5 equiv of N3SO2Ar (Ar = C6H4Me-4) furnished the novel ionic phosphazide [[N(CH2CH2NMe)3P]2(mu-N3)][SO2Ar] (6). Data that shed light on the mechanistic pathway leading to 3 were obtained by low temperature 31P NMR spectroscopy. A crystal and molecular structure analysis of the phosphazide sulfonate [N(CH2CH2NMe)3PN3][SO3C6H4Me-4] (4), obtained by atmospheric oxidation of 3, indicated an ionic structure, the cationic part of which is stabilized by a transannular P-N bond. A crystal and molecular structure analysis of 6 also indicated an ionic structure in which the cation features two untransannulated N(CH2CH2NMe)3P cages bridged by an azido group in an eta 1: mu: eta 1 fashion. The reaction of P(NMe2)3 with N3SO2Ar (Ar = C6H4Me-4) in a 1:0.5 molar ratio furnished [[(Me2N)3P]2(mu-N3)][SO2-Ar] (11) in quantitative yield. On the other hand, the same reaction involving a 1:1 molar ratio of P(NMe2)3 and N3SO2Ar produced a mixture of 11, [(Me2N)3PN3][SO2Ar] (12), and the iminophosphorane (Me2N)3P=NSO2Ar (10). In contrast, the bicyclic tris(amino)phosphines MeC(CH2NMe)3P (7) and O=P(CH2NMe)3P (8) reacted with N3SO2-Ar (Ar = C6H4Me-4) to give the iminophosphorane MeC(CH2NMe)3P=NSO2Ar (14) (structured by X-ray means) and O=P(CH2NMe)3P=NSO2Ar (16) via the intermediate phosphazides MeC(CH2NMe)3PN3SO2Ar (13) and O=P(CH2NMe)3PN3SO2Ar (15), respectively. The variety of products obtained from the reactions of arylsulfonyl azides with proazaphosphatranes (1 and 2), acyclic P(NMe2)3, bicyclic tris(amino)phosphines 7 and 8 are rationalized in terms of steric and basicity variations among the phosphorus reagents.     

Syntheses and Crystal Structures of Copper（Ⅱ） and Nickel Complexes with 1,2,3-Triazole-carboxylic Acid

Three novel complexes [Cu(L1)2(H2O)2] (1), [Ni(L1)2(H2O)2]·(H2O)4(2,HL1=5-methyl-1-(4-methylphenyl)-1,2,3-triazole-4-carboxylic acid) and [Ni2 (HL2)2(CH3OH)6]·(CH3OH)2(3,H3L2=1,2,3-triazole-4,5-dicarboxylic acid) were synthesized and characterized by elemental analysis, IR and X-ray diffraction. Complexes 1 and 2 are mononuclear structures, and are assembled into a two-dimensional sheet by C(7) H(7)···O(3) weak interactions or hydrogen-bonding interaction. Complex 3 is a centrosymmetric dinuclear structure, and is assembled into a three-dimensional supramolecular structure by hydrogen-bonding interaction.     

Surface tension of binary mixtures of imidazolium and ammonium based ionic liquids with alcohols, or water: cation, anion effect

The surface tensions were measured at atmospheric pressure, with use of a ring tensiometer, of a series of alcoholic solutions of closely related ionic liquids: 1-methyl-3-methylimidazolium methylsulfate, [MMIM][CH3SO4] in alcohol (methanol, or ethanol, or 1-butanol at 298.15 K), 1-butyl-3-methylimidazolium methylsulfate, [BMIM][CH3SO4] in alcohol (methanol, or ethanol, or 1-butanol at 298.15 K), 1-butyl-3-methylimidazolium octylsulfate, [BMIM][OcSO4] in alcohol (methanol, or 1-butanol at 298.15 K) and of 1-hexyloxymethyl-3-methylimidazolium tetrafluoroborate, [C6H(13)OCH2MIM][BF4], 1,3-dihexyloxymethylimidazolium tetrafluoroborate, [(C6H13OCH2)2IM][BF4] in alcohol (methanol, or 1-butanol, or 1-hexanol at 308.15 and 318.5 K) and hexyl(2-hydroxyethyl)dimethylammonium bromide, C6Br in 1-octanol at 298.15 K. The set of ammonium ionic liquids of different cations and anions (C2Br, C2BF4, C2PF6, C2N(CN)2, C3Br, C4Br and C6Br) was chosen to show the influence of small amount of the ammonium ionic liquid on the surface tension of water at 298.15 K. The influence of the cation, or anion alkyl chain length on the properties under study (densities and surface tension) was tested.     

Synthesis, spectroscopic, and structural studies on transition metal complexes involving homoleptic tripodal selenoether and telluroether coordination

The reaction of [MCl2(NCMe)2] (M = Pd or Pt) with 2 molar equiv of MeC(CH2ER)3 (E = Se, R = Me; E = Te, R = Me or Ph) and 2 molar equiv of TlPF6 affords the bis ligand complexes [M(MeC(CH2ER)3)2][PF6]2. The crystal structure of [Pt(MeC(CH2SeMe)3)2][PF6]2 (C16H36F12P2PtSe6, a = 12.272(10) A, b = 18.563(9) A, c = 15.285(7) A, beta = 113.18(3) degrees, monoclinic, P2(1)/n, Z = 4) confirms distorted square planar Se4 coordination at Pt(II), derived from two bidentate tripod selenoethers with the remaining arm not coordinated and directed away from the metal center. Solution NMR studies indicate that these species are fluxional and that the telluroether complexes are rather unstable in solution. The octahedral bis tripod complexes [Ru(MeC(CH2SMe)3)2][CF3-SO3]2 and [Ru(MeC(CH2TePh)3)2][CF3SO3]2 are obtained from [Ru(dmf)6][CF3SO3]3 and tripod ligand in EtOH solution. The thioether complex (C18H36F6O6RuS8, a = 8.658(3) A, b = 11.533(3) A, c = 8.659(2) A, alpha = 108.33(2) degrees, beta = 91.53(3) degrees, gamma = 106.01(2) degrees, triclinic, P1, Z = 1) is isostructural with its selenoether analogue, involving two facially coordinated trithioether ligands in the syn configuration. NMR spectroscopy confirms that this configuration is retained in solution for all of the bis tripod Ru(II) complexes. These low-spin d6 complexes show unusually high ligand field splittings. The hexaselenoether Rh(III) complex [Rh(MeC(CH2SeMe)3)2][PF6]3 was obtained by treatment of [Rh(H2O)6]3+ with 2 molar equiv of MeC(CH2SeMe)3 in aqueous MeOH in the presence of excess PF6- anion, while the iridium(III) analogue [Ir(MeC(CH2SeMe)3)2][PF6]3 was obtained via the reaction of the Ir(I) precursor [IrCl(C8H14)2]2 with the selenoether tripod in MeOH/aqueous HBF4. NMR studies reveal different invertomers in solution for both the Rh and Ir species. The Cu(I) complexes [Cu(MeC(CH2ER)3)2]PF6 were obtained from [Cu(NCMe)4]PF6 and tripod ligand in CH2Cl2 solution. The corresponding Ag(I) species [Ag(MeC(CH2TeR)3)2]CF3SO3 (R = Me or Ph) were obtained from Ag[CF3SO3] and tripod telluroether. In contrast, a similar reaction with 2 molar equiv of MeC(CH2SeMe)3 afforded only the 1:1 complex [Ag(MeC(CH2SeMe)3)]CF3SO3. The structure of this species (C9H18AgF3O3SSe3, a = 8.120(3) A, b = 15.374(3) A, c = 14.071(2) A, beta = 93.86(2) degrees, monoclinic, P2(1)/n, Z = 4) reveals a distorted trigonal planar geometry at Ag(I) derived from one bidentate selenoether and one monodentate selenoether. These units are then linked to adjacent Ag(I) ions to give a one-dimensional linear chain cation.     

Novel cation [N(SO2NMe3)2]+ and its synthesis and crystal structure. Dichloride of imido-bis(sulfuric) acid HN(SO2Cl)2. Part 1. Crystal structures of KN(SO2Cl)2.(1/2)CH3CN, KN(SO2Cl)2.(1/6)CH2Cl2, and [PCl4][N(SO2Cl)2

Several salts of bis(chlorosulfonyl)imide HN(SO2Cl)2 (1), namely, two solvates of its potassium salt, KN(SO2Cl)2.(1/2)CH3CN (1K1), KN(SO2Cl)2.(1/6)CH2Cl2 (1K2), and its tetrachlorophosphonium salt, [PCl4][N(SO2Cl)2] (2), were prepared and structurally characterized. The reaction of HN(SO2Cl)2 with Me3N gives the [N(SO2Cl)2]- salt of a novel cation, [N(SO2NMe3)2]+. This cation is analogous to the [HC(SO2NMe3)2]+ cation, but in contrast to the latter, it is fairly stable to hydrolysis. The salt [N(SO2NMe3)2]+[N(SO2Cl)2]- (3) can be converted into salts of other anions by being treated with diluted aqueous solutions of the respective acids, and thus NO3-, Cl-.H2O, SeO3(2-), CH3COO-, HSO4-, (COO)2(2-) salts were prepared. Treatment of 3 with concentrated HNO3 gave the [N(SO2NMe3)2]+ [O2NO-H-ONO2]- salt, and the addition of an HCl-acidified FeCl3 aqueous solution yielded the FeCl4- salt. Methanolysis resulted in the formation of MeOSO3- and [MeOSO2NSO2OMe]- salts. All salts have been characterized by chemical analysis, vibrational spectroscopy, and X-ray structure determinations.     

Reversible, metal-free hydrogen activation by frustrated Lewis pairs

The Lewis acid cyclohexylbis(pentafluorophenyl)boron 1, which exhibits about 15% lower Lewis acidity in comparison with B(C(6)F(5))(3), activates H(2) in the presence of the bulky Lewis bases 2,2,6,6-tetramethylpiperidine (TMP), 1,2,2,6,6-pentamethylpiperidine (PMP), tri-tert-butylphosphine (t-Bu(3)P) leading in facile reactions at room temperature to heterolytic splitting of dihydrogen and formation of the salts [TMPH][CyBH(C(6)F(5))(2)] 2, [PMPH][CyBH(C(6)F(5))(2)] 3 and [t-Bu(3)PH][CyBH(C(6)F(5))(2)] 4, which could be dehydrogenated at higher temperatures. The related Lewis acid 1-phenyl-2-[bis(pentafluorophenyl)boryl]ethane 5 exhibiting about 10% lower Lewis acidity than B(C(6)F(5))(3) is also capable of splitting H(2) in a heterolytic fashion in the presence of TMP, PMP and t-Bu(3)P yielding [TMPH][PhC(2)H(4)BH(C(6)F(5))(2)] 6, [PMPH][PhC(2)H(4)BH(C(6)F(5))(2)] 7 and [t-Bu(3)PH][PhC(2)H(4)BH(C(6)F(5))(2)] 8. Under comparable conditions as for 2-4, the dehydrogenations of 6-8 were much slower. 4b and 6 were characterized by single crystal X-ray diffraction studies.     

Brønsted acidic ionic liquids and their zwitterions: synthesis, characterization and pKa determination

Imidazolium chlorides with one or two carboxylic acid substituent groups, 1-methyl-3-alkylcarboxylic acid imidazolium chloride, [Me[(CH2)nCOOH]im]Cl (n=1, 3), and 1,3-dialkylcarboxylic acid imidazolium chloride, [[(CH2)nCOOH]2im]Cl (n=1, 3), have been synthesized via their corresponding acid esters. Deprotonation of the carboxylic acid functionalized imidazolium chlorides with triethylamine affords the corresponding zwitterions [Me[(CH2)nCOO]im] (n=1, 3) and [[(CH2)nCOOH][(CH2)nCOO]im] (n=1, 3). Subsequent reaction of the zwitterions with strong acids gives the new imidazolium salts [Me[(CH2)nCOOH]im]X (n=1, 3; X=BF4, CF3SO3) and [[(CH2)nCOOH]2im]X (n=1, 3; X=BF4, CF3SO3), which exhibit melting points as low as -61 degrees C. The solid-state structures of two of the carboxylic acid functionalized imidazolium salts have been determined by single-crystal X-ray diffraction analysis. Extensive hydrogen bonding is present between the chloride and the imidazolium, with eight Cl.H interactions below 3 A. The pK(a) values of all the salts, determined by potentiometric titration, lie between 1.33 and 4.59 at 25 degrees C.     

Structural variation in organically templated uranium sulfate fluorides

The ability of templated uranium sulfate fluorides to adopt diverse inorganic architectures is demonstrated in six novel materials. The inorganic structures present in [N2C6H16][UO2F2(SO4)](USFO-2), [N2C6H16][UO2F(SO4)]2(USFO-3), [N2C3H12][UO2F(SO4)]2.H2O (USFO-4), [N2C5H14][UO2F(H2O)(SO4]2(USFO-5), [N2C6H18]2[UO2F(SO4)]4.H2O (USFO-6) and [N2C3H12][UO2F(SO4)]2.H2O (USFO-7) range from infinite chains to five different layer topologies. The chain, and two of the five layers, have unprecedented structure types. These compounds illustrate the structural diversity within this new family of materials, arising from the varied coordination of the U6+ centres. Each material was synthesised under hydrothermal conditions, through reaction of uranyl acetate, sulfuric acid, HF(aq), water, and the respective organic template.     

Synthesis and reactivity of fluorinated ferracarborane anions

The ferracarborane [N(PPh3)2][6,6,6,10,10,10-(CO)6-closo-6,10,1-Fe2CB7H8] reacts in CH2Cl2 with 3 molar equivalents of Ag[PF6] to yield the trifluoro-substituted species [N(PPh3)2][7,8,9-F3-6,6,6,10,10,10-(CO)6-closo-6,10,1-Fe2CB7H5]. Compound undergoes structural rearrangement in toluene at reflux temperatures, forming [N(PPh3)2][8,9,10-F3-6,6,6,7,7,7-(CO)6-closo-6,7,1-Fe2CB7H5]. Alternatively, reaction of either or with a 10-fold excess of Ag[PF6] in CH2Cl2 forms two species: namely, [N(PPh3)2][2,7,9,10-F4-6,6,6,8,8,8-(CO)6-closo-6,8,1-Fe2CB7H4], in which one further B-F substitution has occurred and the {Fe2CB7} cluster core has rearranged, plus a mono-iron co-product, [N(PPh3)2][3,8,9-F3-7,7,7-(CO)3-closo-7,1-FeCB7H5] that is formed by polyhedral contraction. Treatment of with [NO][BF4] in CH2Cl2 results in CO substitution at the 4-connected iron vertex [Fe10], producing the zwitterionic complex [7,8,9-F3-6,6,6,10,10-(CO)5-10-NO-closo-6,10,1-Fe2CB7H5]. Addition of Me3NO to a mixture of and PEt3 in CH2Cl2 also results in CO substitution, forming the isomeric species [N(PPh3)2][7,8,9-F3-6,6,m,10,10-(CO)5-n-PEt3-closo-6,10,1-Fe2CB7H5] [m=6, n=10; m=10, n=6] in a 5:1 ratio. Treatment of with [NO][BF4] and then CNBut in CH2Cl2 allows further, successive CO substitution at Fe10 to yield first a neutral, zwitterionic complex [7,8,9-F3-6,6,6,10-(CO)4-10-NO-10-PEt3-closo-6,10,1-Fe2CB7H5] and then [7,8,9-F3-6,6,6-(CO)3-10-CNBut-10-NO-10-PEt3-closo-6,10,1-Fe2CB7H5]. The molecular structures of compounds and have been established by X-ray diffraction.     

若干镧系络合物的空间群

摘要 藉助模拟强度精修将九个镧系络合物晶体结构的空间群作了修正 .（ 1） NaN[Nd(DMSO)5(H2O)3]Cl3· 3H2O从 P1修正为 P;（ 2） Er(ClO4)3· 6(CH3)2NC(O)N(CH3)2从 P修正为 R;（ 3） Nd(O3SCF3)3· DMF· 6H2O从 P1修正为 R3m;(4)[NaNCCH3][Nd{S2CN(CH2CH3)2}4]从 P修正为 C 2/c;(5)[(CH3)2NCS2]3La· 2DMSO从 Cc修正为 C 2/c;（ 6） Yb(C9H7)2· 2THF从 Cc修正为 C 2/c;（ 7） [(C6H5)3Ge]2Yb· 4THF从 P21修正为 P 2;(8)TlPr(C36H44N4)2从 Pna2,修正为 Pnma;(9)[CuLaSm(C4O4)4(H2O)16]· 2H2O从 P2修正为 P2.（ 8）、（ 9）两个络合物结构从非心修正到有心时,不仅改进了键长与键角值,而且影响到分子结构特征的描述 .     

Relative Lewis basicities of six AI(ORF)4- superweak anions and the structures of LiA

The relative Lewis basicities of six Al(ORF)4- ions, Al[OC(CH3)(CF3)2]4-, Al(OC(CF3)3]4-, Al(OCPh(CF3)2]4-, Al[OC[4-C6H4(tBu)](CF3)2]4-, Al(OC(Cy)(CF3)2]4-, and Al(OCPh2(CF3)]4-, have been determined by measuring their relative coordinating abilities towards Li+ in dichloromethane. The relative Li- Lewis basicities of the Al(ORF)4- ions are linearly related to the aqueous pKa values of the corresponding parent HORF fluoroalcohols. The Lewis basicity of Al[OCH(CF3)2]4- could not be measured because two of these anions can coordinate to one Li+ cation. The structures of LiAl[OCH(CF3)2]4 and [1-Et-3-Me-1,3-C3H3N2][Li[Al[OCH(CF3)2)4]2] were determined.     

Diazo complexes of rhenium: preparations and crystal structures of the bis(dinitrogen), [Re(N2)2(PPh(OEt)2)4][BPh4] and methyldiazenido [ReCl(CH3N2)(CH3NHNH2)(PPh(OEt)2)3][BPh4] derivatives

Depending on experimental conditions and the nature of the hydrazine, the reactions of ReCl3P3 [P = PPh(OEt)2] with RNHNH2 (R = H, CH3, tBu) afford the bis(dinitrogen) [Re(N2)2P4]+ (2+), dinitrogen ReClN2P4 (3), and methyldiazenido [ReCl(CH3N2)(CH3NHNH2)P3]+ (1+) derivatives. In contrast, reactions of ReCl3P3 [P = PPh(OEt)2, PPh2OEt] with arylhydrazines ArNHNH2 (Ar = Ph, p-tolyl) give the aryldiazenido cations [ReCl(ArN2)(ArNHNH2)P3]+ (4+) and [ReCl(ArN2)P4]+ (7+) and the bis(aryldiazenido) cations [Re(ArN2)2P3]+ (5+, 6+). These complexes were characterized spectroscopically (IR; 1H and 31P NMR), and the BPh4 complexes 1, 2, and 7 were characterized crystallographically. The methyldiazenido derivative [ReCl(CH3N2)(CH3NHNH2)(PPh(OEt)2)3][BPh4] (1) crystallizes in space group P1 with a = 15.396(5) A, b = 16.986(5) A, c = 11.560(5) A, alpha = 93.96(5) degrees, beta = 93.99(5) degrees, gamma = 93.09(5) degrees, and Z = 2 and contains a singly bent CH3N2, group bonded to an octahedral central metal. One methylhydrazine ligand, one Cl- trans to the CH3N2, and three PPh(OEt)2 ligands complete the coordination. The complex [Re(N2)2(PPh(OEt)2)4][BPh4] (2) crystallizes in space group Pbaa with a = 23.008(5) A, b = 23.367(5) A, c = 12.863(3) A, and Z = 4. The structure displays octahedral coordination with two end-on N2 ligands in mutually trans positions. [ReCl(PhN2)(PPh(OEt)2)4][BPh4] (7) crystallizes in space group P2(1)/n with a = 19.613(5) A, b = 20.101(5) A, c = 19.918(5) A, beta = 115.12(2) degrees, and Z = 4. The structure shows a singly bent phenyldiazenido group trans to the Cl- ligand in an octahedral environment. The dinitrogen complex ReClN2P4 (3) reacts with CF3SO3CH3 to give the unstable methyldiazenido derivative [ReCl(CH3N2)P4][BPh4]. Reaction of the methylhydrazine complex [ReCl(CH3N2)(CH3NHNH2)P3][BPh4] (1) with Pb(OAc)4 at -30 degrees C results in selective oxidation of the hydrazine, affording the corresponding methyldiazene derivative [ReCl(CH3N=NH)(CH3N2)P3][BPh4] (8). In contrast, treatment with Pb(OAc)4 of the related arylhydrazines [ReCl(ArN2)(ArNHNH2)P3][BPh4] (4) [P = PPh(OEt)2] gives the bis(aryldiazenido) complexes [Re(ArN2)2P3][BPh4] (5). Possible protonation reactions of Br?nsted acids HX with all diazenides, 1, 4, 5, 6, and 8, were investigated and found to proceed only in the cases of the bis(aryldiazenido) complexes 5 and 6, affording, with HCl, the octahedral [ReCl(ArN=NH)(ArN2)P3][BPh4] or [ReCl(Ar(H)NN)(ArN2)P3][BPh4] (10) (Ar = Ph; P = PPh2OEt) derivative.     

Photochemical reactions of [CH2(eta5-C5H4)2][Rh(C2H4)2]2 with silanes: evidence for Si-C and C-H activation pathways

Photochemical reaction of [CH2(eta5-C5H4)2][Rh(C2H4)2]2 1 with dmso led to the stepwise formation of [CH2(eta5-C5H4)2][Rh(C2H4)2][Rh(C2H4)(dmso)] 2a and [CH2(eta5-C5H4)2][Rh(C2H4)(dmso)]2 2b. Photolysis of 1 with vinyltrimethylsilane ultimately yields three isomeric products of [CH2(eta5-C5H4)2][Rh(CH2=CHSiMe3)2]2, 3a, 3b and 3c which are differentiated by the relative orientations of the vinylsilane. When this reaction is undertaken in d6-benzene, H/D exchange between the solvent and the alpha-proton of the vinylsilane is revealed. In addition evidence for two isomers of the solvent complex [CH2(eta5-C5H4)2][Rh(C2H4)2][Rh(C2H4)(eta2-toluene)] was obtained in these and related experiments when the photolysis was completed at low temperature without substrate, although no evidence for H/D exchange was observed. Photolysis of 1 with Et3SiH yielded the sequential substitution products [CH2(eta5-C5H4)2][Rh(C2H4)2][Rh(C2H4)(SiEt3)H] 4a, [CH2(eta5-C5H4)2][Rh(C2H4)(SiEt3)H]2 4b, [CH2(eta5-C5H4)2][Rh(C2H4)(SiEt3)H][Rh(SiEt3)2(H)2] 4c and [CH2(eta5-C5H4)2][Rh(SiEt3)2(H)2]2 4d; deuteration of the alpha-ring proton sites, and all the silyl protons, of 4d was demonstrated in d6-benzene. This reaction is further complicated by the formation of two Si-C bond activation products, [CH2(eta5-C5H4)2][RhH(mu-SiEt2)]2 5 and [CH2(eta5-C5H4)2][(RhEt)(RhH)(mu-SiEt2)2] 6. Complex 5 was also produced when 1 was photolysed with Et2SiH2. When the photochemical reactions with Et3SiH were repeated at low temperatures, two isomers of the unstable C-H activation products, the vinyl hydrides [CH2(eta5-C5H4)2][{Rh(SiEt3)H}{Rh(SiEt3)}(mu-eta1,eta2-CH=CH2)] 7a and 7b, were obtained. Thermally, 4c was shown to form the ring substituted silyl migration products [(eta5-C5H4)CH2(C5H3SiEt3)][Rh(SiEt3)2(H)2]2 8 while 4b formed [CH2(C5H3SiEt3)2][Rh(SiEt3)2(H)2]2 (9a and 9b) upon reaction with excess silane. The corresponding photochemical reaction with Me3SiH yielded the expected products [CH2(eta5-C5H4)2][Rh(C2H4)2][Rh(C2H4)(SiMe3)H] 10a, [CH2(eta5-C5H4)2][Rh(C2H4)(SiMe3)H]2 10b, [CH2(eta5-C5H4)2][Rh(C2H4)(SiMe3)H][Rh(SiMe3)2(H)2] 10c and [CH2(eta5-C5H4)2][Rh(SiMe3)2(H)2]2 10d. However, three Si-C bond activation products, [CH2(eta5-C5H4)2][(RhMe)(RhH)(mu-SiMe2)2] 11, [CH2(eta5-C5H4)2][(Rh{SiMe3})(RhMe)(mu-SiMe2)2] 12 and [CH2(eta5-C5H4)2][(Rh{SiMe3})(RhH)(mu-SiMe2)2] 13 were also obtained in these reactions.     

Template- and pH-directed assembly of diruthenium diphosphonates with different topologies and oxidation states

In the presence of organic templates, six diruthenium diphosphonates, namely, [H3N(CH2)3NH3]2[Ru2(hedp)2] (1), [H3N(CH2)4NH3]2[Ru2(hedp)2].4H2O (2), [H3N(CH2)5NH3]2[Ru2(hedp)2].4H2O (3), [H3N(CH2)3NH3][Ru2(hedp)(hedpH)].H2O (4), [H3N(CH2)4NH3][Ru2(hedpH(0.5))2].2H2O (5), and [H3N(CH2)5NH3]2[Ru2(hedp)2][Ru2(hedpH)2]] (6) [hedp = 1-hydroxyethylidenediphosphonate, CH3C(OH)(PO3)2] have been synthesized under hydrothermal conditions. Compounds 1-3 contain homovalent paddlewheel cores of Ru2(II,II)(hedp)2(4-) that are connected through edge-sharing of the [RuO5Ru] octahedra, resulting in infinite linear chains. Compounds 4-6 contain mixed-valent diruthenium(II,III) phosphonate paddlewheel cores of Ru2(II,III)(hedpH(n))2(3-2n)- that are connected by phosphonate oxygen atoms, forming distorted square-grid layers in 4 and 6 or a kagomé lattice in 5. Both the templates and the pH values are found to play important roles in directing the final products with particular topologies and oxidation states of the diruthenium unit. The magnetic studies show that weak antiferromagentic interactions are propagated between the homovalent diruthenium units in compounds 1-3. For compounds 4-6, weak ferromagnetic interactions are observed.     

Reactivity of boranes with a titanium(IV) amine tris(phenolate) alkoxide complex; formation of a Ti(IV) tetrahydroborate complex, a Ti(III) dimer and a Ti(IV) hydroxide Lewis acid adduct

Treatment of the titanium(IV) alkoxide complex [Ti(Oi Pr)(OC6Me2H(2)CH2)3N] (2) with BH3.THF, as part of a study into the utility and reactivity of (2) in the metal mediated borane reduction of acetophenone, results in alkoxide-hydride exchange and formation of the structurally characterised titanium(iv) tetrahydroborate complex [Ti{BH4}(OC6Me2H2CH2)3N] (3). Complex (3) readily undergoes reduction to form the isolable titanium(III) species [Ti(OC6Me2H2CH2)3N]2 (4). Reaction of (2) with B(C6F5)3 results in formation of the Lewis acid adduct [Ti(OC6Me2H2CH2)3N][HO.B(C6F5)3] (5). In comparison, treatment of the less sterically encumbered alkoxide Ti(Oi Pr)4 with B(C6F5)3 results in alkoxide-aryl exchange and formation of the organometallic titanium complex [Ti(Oi Pr)3(C6F5)]2 (6). The molecular structures of 3, 4, 5 and 6 have been determined by X-ray diffraction.     

Organobismuth compounds with the pincer ligand 2,6-(Me2NCH2)2C6H3: monoorganobismuth(III) carbonate, sulfate, nitrate, and a diorganobismuthenium(III) salt

The reaction of RBiCl(2) (1) [R = 2,6-(Me(2)NCH(2))(2)C(6)H(3)] with Na(2)CO(3) or Ag(2)SO(4) (1 : 1 molar ratio) gave RBiCO(3) (2) and RBiSO(4) (3), respectively. RBi(NO(3))(2) (4) was obtained from RBiCl(2) and AgNO(3) (1 : 2 molar ratio). The ionic complex [R(2)Bi][W(CO)(5)Cl] (6) was obtained from R(2)BiCl (5) and W(CO)(5)(THF), following an unusual chlorine transfer from bismuth to tungsten. Compounds 2-4 are partially soluble in water. The molecular structures of 2·0.5CH(2)Cl(2), 3, 4·H(2)O and 6 were established by single-crystal X-ray diffraction. The carbonate 2 and the sulfate 3 exhibit a polymeric structure based on bridging oxo anions, while for the compound 4 dimer associations are formed, with both bridging and terminal nitrate anions. Dimer associations, based on weak Cl···H interactions between the cation and the anion, were found in the crystal of 6.