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1.
Alonso M Alvarez MA García ME Ruiz MA Hamidov H Jeffery JC 《Inorganic chemistry》2010,49(24):11595-11605
The anionic oxophosphinidene complexes (H-DBU)[MCp{P(O)R*}(CO)(2)] (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3); Cp = η(5)-C(5)H(5), DBU = 1,8-diazabicyclo [5.4.0] undec-7-ene) displayed multisite reactivity when faced with different electrophilic reagents. The reactions with the group 14 organochloride compounds ER(4-x)Cl(x) (E = Si, Ge, Sn, Pb) led to either phosphide-like, oxophosphinidene-bridged derivatives [MCp{P(OE')R*}(CO)(2)] (E' = SiMe(3), SiPh(3), GePh(3), GeMe(2)Cl) or to terminal oxophosphinidene complexes [MCp{P(O)R*}(CO)(2)(E')] (E' = SnPh(3), SnPh(2)Cl, PbPh(3); Mo-Pb = 2.8845(4) ? for the MoPb compound). A particular situation was found in the reaction with SnMe(3)Cl, this giving a product existing in both tautomeric forms, with the phosphide-like complex [MCp{P(OSnMe(3))R*}(CO)(2)] prevailing at room temperature and the tautomer [MCp{P(O)R*}(CO)(2)(SnMe(3))] being the unique species present below 203 K in dichloromethane solution. The title anions also showed a multisite behavior when reacting with transition-metal based electrophiles. Thus, the reactions with the complexes [M'Cp(2)Cl(2)] (M' = Ti, Zr) gave phosphide-like derivatives [MCp{P(OM')R*}(CO)(2)] (M = Mo, M' = TiCp(2)Cl, ZrCp(2)Cl; M = W, M' = ZrCp(2)Cl), displaying a bridging κ(1),κ(1)-P,O- oxophosphinidene ligand connecting MCp(CO)(2) and M'Cp(2)Cl metal fragments (W-P = 2.233(1) ?, O-Zr = 2.016(4) ? for the WZr compound]. In contrast, the reactions with the complex [AuCl{P(p-tol)(3)}] gave the metal-metal bonded derivatives trans-[MCp{P(O)R*}(CO)(2){AuP(p-tol)(3)}] (M = Mo, W; Mo-Au = 2.7071(7) ?). From all the above results it was concluded that the terminal oxophosphinidene complexes are preferentially formed under conditions of orbital control, while charge-controlled reactions tend to give derivatives with the electrophilic fragment bound to the oxygen atom of the oxophosphinidene ligand (phosphide-like, oxophosphinidene-bridged derivatives). 相似文献
2.
Hayrullah Ayik 《Czechoslovak Mathematical Journal》2005,55(2):455-463
Let T=[S; I; J; P] be a Rees matrix semigroup where S is a semigroup, I and J are index sets, and P is a J × I matrix with entries from S, and let U be the ideal generated by all the entries of P. If U has finite index in S, then we prove that T is periodic (locally finite) if and only if S is periodic (locally finite). Moreover, residual finiteness and having solvable word problem are investigated. 相似文献
3.
J.M. Howie proved that $\operatorname {Sing}_{n}$ , the semigroup of all singular mappings of {1,…,n} into itself, is generated by its idempotents of defect 1 (in J. London Math. Soc. 41, 707–716, 1966). He also proved that if n≥3 then a minimal generating set for $\operatorname {Sing}_{n}$ contains n(n?1)/2 transformations of defect 1 (in Gomes and Howie, Math. Proc. Camb. Philos. Soc. 101. 395–403, 1987). In this paper we find necessary and sufficient conditions for any set for transformations of defect 1 in $\operatorname {Sing}_{n}$ to be a (minimal) generating set for $\operatorname {Sing}_{n}$ . 相似文献
4.
Boron industrial solid waste is used as reinforcement for preparing composite materials. This waste has boron trioxide which holds unique properties may affect the surface or interface of the composite. The prepared composites are characterized in order to determine the dispersion and the structure by means of inverse gas chromatography (IGC), Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). There is a strong relation between the dispersion of reinforcement and the properties of newly formed composite. The dispersive component of the surface energies of the composites and components are determined by IGC. This parameter is difficult to measure by other methods and it is related to the wettability and adhesive characters of solid materials. The effect of compounding ratios of reinforcement is also examined. Furthermore, XRD diffractograms and SEM images of composites showed well dispersion. Thermal analysis revealed that the addition of the boron industrial solid waste to the polymer increased the thermal stability of pure polymer. Infrared spectra of the composites indicated that the composites were formed from the waste reinforcement and the polymer matrix. 相似文献
5.
Isil Topaloglu Sozuer Alev Gunyar John J. Jeffery Hayrullah Hamidov 《Transition Metal Chemistry》2004,29(7):780-785
Reaction of the oxo-molybdenum(V) compound, [MoTp*(O)Cl2], [Tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate] with p-methoxy and p-nitroaniline in the presence of Et3N under N2, afforded the oxo-bridged oxo(arylimido) molybdenum(V) complexes, [MoTp*(O)Cl](-O)[MoTp*(Cl)(NC6H4R)] (1, R=OMe; 2, R=NO2). The new compounds were characterized by elemental analysis, i.r., mass, and 1H-n.m.r. spectra. The single crystal X-ray crystallographic determination of [MoTp*(O)Cl](-O)[MoTp*(Cl)(NC6H4OMe)] was carried out to confirm that there is a Mo—O—Mo bridge and a near linear arylimido group in the structure. 相似文献
6.
Let P n and T n be the partial transformation and the full transformation semigroups on the set {1,…, n}, respectively. In this paper we find necessary and sufficient conditions for any set of partial transformations of height r in the subsemigroup PK(n, r) = {α ∈P n : |im (α)| ≤r} of P n to be a (minimal) generating set of PK(n, r); and similarly, for any set of full transformations of height r in the subsemigroup K(n, r) = {α ∈T n : |im (α)| ≤r} of T n to be a (minimal) generating set of K(n, r) for 2 ≤ r ≤ n ? 1. 相似文献
7.
Alonso M Alvarez MA García ME Ruiz MA Hamidov H Jeffery JC 《Journal of the American Chemical Society》2005,127(43):15012-15013
The (H-DBU)+ salt of the anionic phosphinidene oxide complex [MoCp(CO)2{P(O)R*}]- (1) (DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene; R* = 2,4,6-C6H2tBu3) reacts with different oxidizing agents, displaying a multisite activity located at the Mo and P atoms or at the Mo=P bond. Thus, reaction of 1 with [FeCp2]BF4 gives the dimer [Mo2Cp2(CO)4{P(O)R*}2], and reaction with bromine gives the phosphinous acid complex [MoBrCp{P(OH)(CH2CMe2C6H2tBu2}(CO)2], the latter arising from an unprecedented C-H bond addition to the oxide P=O moiety. In contrast, reaction of 1 with p-benzoquinone occurs at the P site to give the P,O-bound phosphonite complex [MoCp{kappa2-OP(OC6H4OH)R*}(CO)2]. Finally, oxygen or sulfur atoms are added to the Mo=P bond by reaction of 1 with Me2CO2 and S8 to give the novel dioxophosphorane or thiooxophosphorane complexes [MoCp(CO)2{kappa2-EP(O)R*}]- (E = O, S). The thiooxophosphorane anion is a good nucleophile and is methylated at either the S or O positions depending on the electrophile used (MeI or (Me3O)BF4) to give the isomers [MoCp{kappa2-(MeS)P(O)R*}(CO)2] and [MoCp{kappa2-SP(OMe)R*}(CO)2], both having novel organophosphorus ligands. 相似文献
8.
Demet Topaloğlu Yazıcı Hayrullah Çetinkaya Musa Şölener Adile Albayrak 《International Journal of Polymer Analysis and Characterization》2017,22(6):483-489
The surface properties of newly synthesized N-methoxy isopropyl acrylamide, N-methoxy isopropyl methacrylamide, cyclo propyl acrylamide, and cyclo propyl methacrylamide polymers were investigated using inverse gas chromatography. The highest dispersive component of the surface energy value was obtained for cyclo propyl methacrylamide at 30°C. The values obtained for all polymers were decreasing with the increasing temperature. The values obtained for the acidic and the basic parameters revealed strong basic characters for the surface of N-methoxy isopropyl methacrylamide and cyclo propyl methacrylamide polymers and weak basic characters for the surface of N-methoxy isopropyl acrylamide and cyclo propyl acrylamide polymers. 相似文献
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10.
Let \(I_{n}\) be the symmetric inverse semigroup on \(X_{n}=\{1,\ldots ,n\}\), and let \(DP_{n}\) and \(ODP_{n}\) be its subsemigroups of partial isometries and of order-preserving partial isometries on \(X_{n}\) under its natural order, respectively. In this paper we find the ranks of the subsemigroups \(DP_{n,r}=\{ \alpha \in DP_{n}:|\mathrm {im\, }(\alpha )|\le r\}\) and \(ODP_{n,r}=\{ \alpha \in ODP_{n}: |\mathrm {im\, }(\alpha )|\le r\}\) for \(2\le r\le n-1\). 相似文献