Synthesis, characterization, solid-state photo-luminescence and anti-tumor activity of zinc(II) 4'-phenyl-terpyridine compounds.

Reactions between 4'-phenyl-terpyridine (L) and several Zn(II) salts (sulfate, nitrate, chloride or acetate) led to the formation of the complexes [Zn(2)(mu-O(2)SO(2))(2)L(2)(CH(3)OH)(2)] (1), [Zn(NO(3))L(H(2)O)]NO(3) (2), [Zn(Cl)(2)L] (3) and [Zn(CH(3)COO)(2)L] (4) which were characterized by IR, (1)H NMR and fluorescence spectroscopies, elemental analysis and single crystal X-ray diffraction. In the dinuclear molecule of 1 the Zn atom is hexacoordinated, with a N(3)O(3) coordination environment and forms an octagonal ZnOSOZnOSO metallacycle. In the remaining structures, the metal atom is envisaged as possessing highly distorted N(3)X(2) (X = O or Cl) square pyramid coordination geometries.

Solvent-free microwave-assisted peroxidative oxidation of secondary alcohols to the corresponding ketones catalyzed by copper(ii) 2,4-alkoxy-1,3,5-triazapentadienato complexes.

A facile, efficient and selective solvent-free synthesis of ketones from secondary alcohols with tert-butylhydroperoxide (TBHP) as the oxidant under microwave irradiation is achieved, where the copper(ii) 2,4-alkoxy-1,3,5-triazapentadienato complexes are efficient catalysts providing high yields (up to 100%), TONs (up to 890) and TOFs (up to 1780 h(-1)).

Alkanes to carboxylic acids in aqueous medium: metal-free and metal-promoted highly efficient and mild conversions.

A convenient and clean route to transform, in aqueous medium, various alkanes to carboxylic acids via single-pot carboxylation with CO and water, under mild conditions, has been achieved, proceeding efficiently and selectively even without any metal catalyst and any acid additive, at low temperatures; the relevant hydroxylating role of H(2)O and radical mechanisms are disclosed by radical-trap, H(2)(18)O and DFT studies.

Amavadin and other vanadium complexes as remarkably efficient catalysts for one-pot conversion of ethane to propionic and acetic acids.

Synthetic amavadin Ca[V{ON[CH(CH(3))COO](2)}(2)] and its models Ca[V{ON(CH(2)COO)(2)}(2)] and [VO{N(CH(2)CH(2)O)(3)}], in the presence of K(2)S(2)O(8) in trifluoroacetic acid (TFA), exhibit remarkable catalytic activity for the one-pot carboxylation of ethane to propionic and acetic acids with the former as the main product (overall yields up to 93 %, catalyst turnover numbers (TONs) up to 2.0 x 10(4)). The simpler V complexes [VO(CF(3)SO(3))(2)], [VO(acac)(2)] and VOSO(4) are less active.

Direct and remarkably efficient conversion of methane into acetic acid catalyzed by amavadine and related vanadium complexes. A synthetic and a theoretical DFT mechanistic study.

Vanadium(IV or V) complexes with N,O- or O,O-ligands, i.e., [VO{N(CH2CH2O)3}], Ca[V(HIDPA)2] (synthetic amavadine), Ca[V(HIDA)2], or [Bu4N]2[V(HIDA)2] [HIDPA, HIDA = basic form of 2,2'-(hydroxyimino)dipropionic or -diacetic acid, respectively], [VO(CF3SO3)2], Ba[VO(nta)(H2O)]2 (nta = nitrilotriacetate), [VO(ada)(H2O)] (ada = N-2-acetamidoiminodiacetate), [VO(Hheida)(H2O)] (Hheida = 2-hydroxyethyliminodiacetate), [VO(bicine)] [bicine = basic form of N,N-bis(2-hydroxyethyl)glycine], and [VO(dipic)(OCH2CH3)] (dipic = pyridine-2,6-dicarboxylate), are catalyst precursors for the efficient single-pot conversion of methane into acetic acid, in trifluoroacetic acid (TFA) under moderate conditions, using peroxodisulfate as oxidant.

A new family of luminescent compounds: platinum(II) imidoylamidinates exhibiting pH-dependent room temperature luminescence.

The imidoylamidinate platinum(II) compounds [Pt{NH=C(R)NC(Ph)NPh}2] (R = CH2Ph 2, p-ClC6H43, Ph 4) were prepared by the reaction of the appropriate trans-[PtCl2(RCN)2] with 4 equiv of the amidine PhC(NH)NHPh giving 2-4 and 2 equivs of the salt PhC(=NH)NHPh.HCl. We also synthesized, by the double alkylation of 4 with MeOSO2CF3, complex [Pt{NH=C(Ph)N(Me)C(Ph)=NPh}2][CF3SO3]2 (5) which models the bis-protonated form of 4.

Pop-the-cork strategy in synthetic utilization of imines: stabilization by complexation and activation via liberation of the ligated species.

Treatment of trans-[PtCl(4)(RCN)(2)] (R = Me, Et) with ethanol allowed the isolation of trans-[PtCl(4)[E-NH[double bond]C(R)OEt](2)]. The latter were reduced selectively, by the ylide Ph(3)P[double bond]CHCO(2)Me, to trans-[PtCl(2)[E-NH[double bond]C(R)OEt](2)]. The complexed imino esters NH[double bond]C(R)OEt were liberated from the platinum(II) complexes by reaction with 2 equiv of 1,2-bis(diphenylphosphino)ethane (dppe) in chloroform; the cationic complex [Pt(dppe)(2)]Cl(2) precipitates almost quantitatively from the reaction mixture and can be easily separated by filtration to give a solution of NH[double bond]C(R)OEt with a known concentration of the imino ester.

Metal-hydride bond activation and metal-metal interaction in dinuclear iron complexes with linking dinitriles: a synthetic, electrochemical, and theoretical study.

The dinuclear iron(II)-hydride complexes [[FeH(dppe)(2)](2)(mu-LL)][BF(4)](2) (LL = NCCH=CHCN (1a), NCC(6)H(4)CN (1b), NCCH(2)CH(2)CN (1c); dppe = Ph(2)PCH(2)CH(2)PPh(2)) and the corresponding mononuclear ones, trans-[FeH(LL)(dppe)(2)][BF(4)] (2a-c) were prepared by treatment of trans-[FeHCl(dppe)(2)], in tetrahydrofuran (thf) and in the presence of Tl[BF(4)], with the appropriate dinitrile (in molar deficiency or excess, respectively). Metal-metal interaction was detected by cyclic voltammetry for 1a, which, upon single-electron reversible oxidation, forms the mixed valent Fe(II)/Fe(III) 1a(+) complex. The latter either undergoes heterolytic Fe-H bond cleavage (loss of H(+)) or further oxidation, at a higher potential, also followed by hydride-proton evolution, according to ECECE or EECECEC mechanistic processes, respectively, which were established by digital simulation.

Zinc(II)/ketoxime system as a simple and efficient catalyst for hydrolysis of organonitriles.

The hydrolysis of sterically hindered and unhindered alkyl nitriles, and also of benzyl and phenyl nitriles RCN (R = Me, CH(2)Cl, Et, n-Pr, i-Pr, n-Bu, t-Bu, p-MeOC(6)H(4)CH(2), Ph), to carboxamides is catalyzed by a novel system of superior simplicity consisting of cheap, widely commercially available, and rather environmentally friendly compounds, that is, a ZnX(2)/ketoxime combination, but it does not proceed at all with either the zinc salt or the ketoxime taken alone. The nature of the anion X(-) in the zinc salt (X = NO(3), Cl, CF(3)SO(3)) or of the ketoxime (Me(2)C=NOH, C(4)H(8)C=NOH, C(5)H(10)C=NOH) does not affect strongly the catalytic properties of the system, but the best results were obtained so far with a Zn(NO(3))(2).6H(2)O/2-propanone oxime molar ratio of 1:4; turnover numbers are typically above ca.

Activation of organonitriles toward beta-electrophilic attack. Synthesis and characterization of methyleneamide (azavinylidene) complexes of rhenium.

Treatment of the nitrile complexes cis-[ReCl(NCR)(dppe)(2)] (R = aryl; dppe = Ph(2)PCH(2)CH(2)PPh(2)) with [Et(2)OH][BF(4)] or SiMe(3)CF(3)SO(3) in CH(2)Cl(2) led to the formation of the methyleneamide (alkylideneamide or azavinylidene) compounds cis-[ReCl[NC(E)C(6)H(4)X-4](dppe)(2)]Y [E = H; X = OMe (1b), Me (1c), H (1d), F (1e), or Cl (1f), Y = BF(4); E = SiMe(3), X = Me (1c'), Y = CF(3)SO(3)] and trans-[ReCl[NC(H)C(6)H(4)X-4](dppe)(2)][BF(4)] [X = NEt(2) (2a), OMe (2b), H (2d), F (2e), or Cl (2f)]. They were characterized by multinuclear NMR spectrometry and X-ray crystallography (2e) which shows that the methyleneamide ligand exhibits linear (three-electron donor) geometry and behaves as a strong pi-electron acceptor. The complex (31)P[(1)H] and (1)H [NC(H)C(6)H(4)X-4] NMR patterns for the cis isomers were analyzed as ABCD and ABCDX (X part) spin systems, respectively.