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The reactivity of NbCl 5 , NbF 5 and TaCl 5 with a selection of commercial imines was investigated for the first time by using dichloromethane as reaction medium. NbCl 5 reacted with Ph 2 C NH, in 1:2 molar ratio, affording [Ph 2 C NH 2 ][NbCl 5 (N CPh 2 )], 1 , in 55% yield, as result of imine self-protonation. The iminium salt [PhCH NH t Bu][NbCl 6 ], 2 , was isolated in 52% yield from NbCl 5 and PhCH N t Bu (1:1 molar ratio), while a low yield of [ t Bu 2 C NH 2 ][NbCl 6 ], 3 , was identified from NbCl 5 / t Bu 2 C NH. The 1:1 reactions of NbF 5 with Ph 2 C NH and PhCH N t Bu were accompanied by electron interchange and led to the isolation of the salts [Ph 2 C NH 2 ][NbF 6 ], 4 , and [PhCH NH t Bu][NbF 6 ], 5 , respectively, in ca. 50% yields. Few crystals of [Ph 2 C NH 2 ] 2 [Ta 2 Cl 10 O], 6 , were recovered from TaCl 5 /Ph 2 C NH, the anion being probably generated by the action of adventitious water. Compounds 1 – 6 were characterized by elemental analysis, IR and NMR spectroscopy. The structures of 1 , 4 and 6 were ascertained by X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

The reactions of NbCl 5 with limited amounts (1–2 molar equivalents) of a series of primary, secondary and tertiary amines were investigated in dichloromethane as solvent. The 1:1 reaction of NbCl 5 with NHEt 2 cleanly afforded an equimolar mixture of [NbCl 4 (NEt 2 )] 2 , 1 , and [NH 2 Et 2 ][NbCl 6 ], 2a ; the former product constitutes the first example of structurally characterized Nb(V) chlorido–amido complex. The ammonium salts [NH 3 n Pr][NbCl 6 ], 2b , and [NH 2 i Pr 2 ][NbCl 6 ], 2c , were isolated in 20–30% yields from the 1:1 reactions of NbCl 5 with NH 2 n Pr and NH i Pr 2 , respectively. Cα–H bond activation and Nb(V) to Nb(IV) reduction took place in the reactions of NbCl 5 with NR 3 (R = Bz, Et; Bz = CH 2 Ph). The iminium salt [(PhCH 2 ) 2 N CHPh][NbCl 6 ], 3 , and the ammonium ion [NH(CH 2 Ph) 3 ] + were identified as the prevalent species generated from the 1:1 NbCl 5 /NBz 3 interaction. [NHEt 3 ][NbCl 6 ], 4 , and [NHEt 3 ] 2 [NbCl 6 ], 5 , were isolated in moderate yields from, respectively, the 1:1 and 1:2 molar reactions of NbCl 5 with NEt 3 . The solid state structures of 1 , 2a , 3 , 4 and 5 were ascertained by single crystal X-ray studies. [ABSTRACT FROM AUTHOR]

The 1:1 M reaction of MoCl 5 with Cl(CH 2 ) 2 OH, in dichloromethane at room temperature, proceeded with chlorine–oxygen interchange and HCl release to give MoOCl 3 in 65% yield. The analogous reactions involving i PrOH, MeOH, L -menthol and H 2 O gave impure MoOCl 3 . MoCl 5 reacted with Me 2 N(CH 2 ) 2 OH in 1:1 M ratio affording the 2-chloroammonium salt [Me 2 NH(CH 2 ) 2 Cl] 2 [Mo 2 O 2 Cl 8 ], 1 . The reaction of MoCl 5 with MeO(CH 2 ) 2 OH afforded a mixture of [Mo(κ 2 O , O ′-O(CH 2 ) 2 OMe) 2 Cl 2 ][Mo 2 O 2 Cl 7 ], 2a , and [Mo(κ 2 O , O ′-O(CH 2 ) 2 OMe) 2 Cl 2 ][MoOCl 4 ], 2b . The products 1 , 2a and 2b were characterized by analytical and spectroscopic techniques, and by X-ray diffractometry. The X-ray structure of 2b shows weak anion–anion interactions, therefore 2b might be alternatively viewed as a Mo 2 O 2 Cl 8 2− salt. [ABSTRACT FROM AUTHOR]

Abstract: The rare example of protonated aldehyde salt [4-(OH)-3-(OCH3)C6H3CH( O H)][4-(OH)-3-(OCH3)C6H3CHO][TaF6], 1, was isolated in the solid state by the reaction of 4-hydroxy-3-methoxybenzaldehyde (vanillin) with TaF5 in dichloromethane. The product 1 was characterized by X-ray diffraction and IR spectroscopy. The 1:1 reaction of TaF5 with N,N-dimethylaniline in CH2Cl2 cleanly afforded [TaF4(NMe2C6H5)2][TaF6], 2, which was identified by NMR spectroscopy. Attempts of crystallization of 2 resulted in the isolation of the ammonium salt [NHMe2C6H5][TaF6], 3. [Copyright &y& Elsevier]

Abstract: The interactions of molybdenum pentachloride (1) with a variety of organic compounds were studied in dichloromethane and the metal products were isolated in the solid state. The 3:1molar reactions of 1 with OCRR′ (R=R′=Ph; R=H, R′=2-C6H4Me) afforded the complexes Mo(O)Cl3(OCRR′)2 (R=R′=Ph, 2a; R=H, R′=2-C6H4Me, 2b) in high yields. Compound ▪, 3, was isolated in 35% yield from 1 and 2-acetylfuran. The 1:1 reaction of 1 with phenazine (C12H8N2) 1 resulted in the formation of MoCl5(C12H8N2), 4; the oxydo-chloride derivative Mo(O)Cl3[κ1(N)-C12H8N2], 5, was prepared straightforwardly by addition of phenazine to Mo(O)Cl3, formed in situ upon treatment of 1 with tetrahydrofuran. The addition of a twofold excess of Me2NCH2CH2CO2Me to 1 afforded MoCl4[κ1(N)-Me2NCH2CH2CO2Me]2, 6, in 72% yield. The reaction of 1 with MeO2CC CCO2Me led to a mixture of inseparable products: MoOCl3(κ1-MeO2CC CCO2Me)2, 7a, MoCl5(κ1-MeO2CC CCO2Me), 7b, and MoCl4(κ1-MeO2CC CCO2Me)2, 7c, were recognized by combined EPR/DFT investigation. Analogous DFT/EPR studies were performed on 2b and 4. The X-ray structures of 2a, 3 and 5 were determined; the X-ray structure of 5 represents a rare example of crystallographically-characterized pentacoordinated Mo(V) neutral complex. [Copyright &y& Elsevier]

Abstract: The room temperature reactions of a series of 1,2-dialkoxyalkanes ROCH2CH(R′)OR′′ with MX5 (M=Nb, Ta; X=Br, I) in 1:1 ratio result in single C–O bond cleavage and high-yield formation of the halo-alkoxides MBr4[κ2-OCH2CH(R′)OR′′] or [NbI4{κ1-OCH2CH(R′)OR′′}]2, and equimolar amounts of the corresponding alkyl halides RX. The reaction of NbBr5 with 1,2-dimethoxyethane, dme, proceeds with preliminary formation of the ionic species [NbBr4(κ2-dme)(κ1-dme)][NbBr6], 3b, which has been identified by solution NMR at low temperature and conductivity analyses. The gas-phase structure of 3b has been optimized by DFT calculations, confirming that the dme ligands adopt bidentate and monodentate coordination, respectively. Although the formation of NbOBr3(dme), 4b, 1,4-dioxane and MeBr from NbBr5/dme (ratio 1:2) is an exoergonic process (calculated =−115.96kcalmol−1), it is inhibited at room temperature. High temperature conditions enhance the production of 1,4-dioxane at the expense of selectivity. The dinuclear species NbOBr3(dme)NbBr5 (Nb–O–Nb), 5b, (X-ray) has been isolated in modest yield as byproduct of the room temperature reaction of NbBr5 with dme. In general, the 1:2molar reactions of NbX5 (X=Br, I) with ROCH2CH(R′)OR′′ occur with the exclusion of nearly one equivalent of organic reactant. [Copyright &y& Elsevier]

Abstract: The Group 5 pentahalides MX5 (M=Nb, Ta; X=Cl, Br), 1, react with a variety of epoxides (1,2-epoxybutane, styrene oxide, 2,3-dimethyl-2,3-epoxybutane, epoxycyclohexane, ethylene oxide) in a 1:3 molar ratio to afford the dinuclear dihalide-tris(2-haloalcoholato) complexes [MX2(OR)2(μ-OR)]2 [M=Nb, X=Cl, R=–CH(Et)CH2Cl, 2a; M=Nb, X=Cl, R=–CH2CH(Ph)Cl, 2b; M=Nb, X=Cl, R=–C(Me)2C(Me)2Cl, 2c; M=Nb, X=Br, R=–CH2CH(Ph)Br, 2d; M=Nb, X=Br, R=–C(Me)2C(Me)2Br, 2e; M=Ta, X=Cl, R=–CH(Et)CH2Cl, 2f; M=Ta, X=Cl, ▪, 2g; M=Ta, X=Br, R=–CH2CH2Br, 2h], in moderate to good yields. The products, 2a–h, result from multiple epoxide insertion into metal–halide bonds, and the reactions involving 1,2-epoxybutane and styrene oxide proceed with high regioselectivity. The molecular structure of 2h has been elucidated by X-ray diffraction. Differently, NbF5 adds one equivalent of 2,3-dimethyl-2,3-epoxybutane to give the monomer NbF5[Oce:italic> t )], 3, in high yield, as a result of epoxide to ketone isomerization. The reactions of MF5 (M=Nb, Ta) with other epoxides proceed non-selectively according to various pathways, including formation of C–O and C–F bonds and C–C and C–H cleavages. [Copyright &y& Elsevier]

Abstract: Niobium and tantalum pentahalides, MX5 (1), react with acetic acid and halo-substituted acetic acids, in 1:1 ratio, to give the dinuclear complexes [MX4(μ-OOCMe)]2 [M=Nb, X=Cl, 2a; M=Ta, X=Cl, 2b; Br, 2c] and [MCl4(μ-OOCR)]2 [M=Nb, R=CH2Cl, 4a; CHCl2, 4c; CCl3, 4e; CF3, 4g; CHBr2, 4i; CH2I, 4j; M=Ta, R=CH2Cl, 4b; CHCl2, 4d; CCl3, 4f; CF3, 4h]. The solid state structures of 2b and 4e have been ascertained by X-ray diffraction studies. The reactions of 1 with acetic anhydride and halo-substituted acetic anhydrides result in C–O bond activation and afford 2 and 4, respectively, with concomitant formation of acetyl halides. Moreover, the complexes MCl5[OC(Cl)Me] [M=Nb, 3a; M=Ta, 3b] have been detected in significant amounts within the mixtures of the reactions of MCl5 with acetic anhydride. TaI5 is unreactive, at room temperature, towards both MeCOOH and (MeCO)2O. MF5 react with RCOOH (R=Me, CH2Cl) in 1:1 molar ratio, to afford the ionic compounds [MF4(RCOOH)2][MF6], 5a–d, in high yields. The additions of (RCO)2O (R=Me, CH2Cl) to MF5 give 5, suggesting that anhydride C–H and C–O bonds activation is operative during the course of these reactions. [Copyright &y& Elsevier]

Abstract: Copper(I) acylpyrazolonate derivatives of formula [Cu(Q)(PPh3)2] (HQ=HQC2F5 = 1-phenyl-3-methyl-4-pentafluoropropanoylpyrazol-5-one, HQCF3,CF3 =1-(4-trifluoromethyl)phenyl-3-methyl-4-trifluoroacetylpyrazol-5-one, HQnaph =1-phenyl-3-methyl-4-(1-naphthoyl)pyrazol-5-one, HQfur =1-phenyl-3-methyl-4-furylpyrazol-5-one, HQthi =1-phenyl-3-methyl-4-thienoylpyrazol-5-one, HQCF3,py =1-(2-pyridyl)-3-methyl-4-trifluoromethylpyrazol-5-one) have been synthesized and characterized, both in the solid state and in solution. The isomorphous crystal structures of [Cu(Qfur)(PPh3)2] and [Cu(Qthi)(PPh3)2] and of [Cu(QC2F5)(PPh3)2] show their copper atoms in distorted tetrahedral environments. Apart from the derivative [Cu(Qnaph)(PPh3)2], they are fluxional in chloroform solution, dissociating partially to the [Cu(Q)(PR3)] fragment and free PR3, or existing in solution as [Cu(O2–Q)(PR3)2] or [Cu(O–Q)(PR3)2] species, with CuO2P2 or CuOP2 metal environments, in equilibrium with each other. By contrast, in [Cu(QCF3,py)(PPh3)2] the QCF3,py ligand is coordinated to copper through the nitrogen atoms of the pyrazole and pyridine rings. The latter compound reacts with Zn(BF4)2 · xH2O and [Ru(p-cymene)Cl2]2 affording ionic heterobimetallic adducts. [Copyright &y& Elsevier]

Ionic platinum(II) complexes [PtCl(PPh 3 )(L∧L)][BF 4 ] {L∧L = 2,2′-bipyridyl ( 1 ) 1,10-phenanthroline ( 2 )} and [PtCl(PPh 3 )(L) 2 ][BF 4 ] {L = pyridine ( 3 ), dimethyl sulfoxide ( 4 )} were synthesized by dehalogenation of cis- [PtCl 2 (PPh 3 )(NCMe)], followed by reaction with the suitable ligand. Chelating nitrogen ligands L∧L afforded single products, which were structurally characterized. In the other cases mixtures of geometric (L = pyridine) and/or coordination (L = dimethyl sulfoxide) isomers were observed in solution. In these cases the structures of the less soluble isomers were obtained via single crystal X-ray diffraction. All the complexes were tested in vitro for their antiproliferative activity on three human tumor cell lines: MSTO-211H, HeLa and HepG2. [ABSTRACT FROM AUTHOR]

The 1:1 molar reactions of WCl 6 with a selection of aliphatic amines, in CH 2 Cl 2 at room temperature, led to the isolation of the W(V) salts [amineH][WCl 6 ] (amine = NEt 3 , 1 ; NHEt 2 , 2 ; pyrrolidine, 3 ; NH 2 CH 2 Ph, 4 ), in 47–57% yields. Analogously, [dmpH][WCl 6 ], 5 , was obtained in 55% yield from WCl 6 /3,5-dimethylpyrazole (dmp). The 1:2 molar reactions of WCl 6 with NEt 3 and NH 2 CH 2 Ph afforded the W(IV) salts [NHEt 3 ] 2 [WCl 6 ], 6 , and [NH 3 CH 2 Ph] 2 [WCl 6 ], 7 , in 50–52% yields, respectively. Compounds 1 – 7 were characterized by analytical and spectroscopic methods, in addition the molecular structures of 2 , 5 and 6 were ascertained by single crystal X-ray diffraction studies. A possible pathway regarding the 1:1 molar reaction of WCl 6 with triethylamine is proposed on the basis of DFT calculations. The iminium [PhCH = NH 2 ] + cation was identified as a co-product in the mixtures obtained from WCl 6 and variable amounts of benzylamine. [ABSTRACT FROM AUTHOR]

The mononuclear complexes MoCl 5 L (L = 2,5-dihydrothiophene-1,1-dioxide), 1 , and MoCl 4 L 2 (L = dimethylsulfone, 2 ; diethylsulfone, 3 ; diphenylsulfone, 4 ) were obtained by the reactions of MoCl 5 with the corresponding sulfones at room temperature in dichloromethane, and were characterized by analytical and magnetic data, and by X-ray crystallography in the cases of 1 and 2 . The X-ray structure of 1 is the first one ever reported for an adduct of MoCl 5 with a carbon-containing species. [ABSTRACT FROM AUTHOR]

The reactions of WCl 6 with a selection of carboxylic acids were investigated by using dichloromethane as reaction medium. The addition of pyridine-3-carboxylic acid (niacin) to WCl 6 gave [C 5 H 4 NHC(O)Cl][WOCl 5 ], 1 , in 75% yield via selective Cl/O interchange. WCl 6 reacted with RCO 2 H (R = CH 3 , CBr 3 , CHCl 2 ) in 1:2 ratio resulting in the formation of HCl and the respective acyl chlorides, RC(O)Cl. WOCl 4 (κ 1 -CH 3 CO 2 H), 2 , was isolated from WCl 6 /CH 3 CO 2 H in 41% yield. The 1:2 reaction of WCl 6 with CCl 3 CO 2 H proceeded with HCl release affording a mixture of WCl 5 (O 2 CCCl 3 ), 3 , and WCl 4 (O 2 CCCl 3 ) 2 , 4 . Compound 3 was isolated from WCl 6 /CCl 3 CO 2 H (1:1 ratio) in 60% yield. All the metal products were characterized by analytical and spectroscopic techniques. The crystal structure of 1 was ascertained by X-ray diffractometry. DFT calculations were carried out in order to shed light into structural, mechanistic and thermodynamic features. [ABSTRACT FROM AUTHOR]

Abstract: Fast oxidations of the iron(II) N,N-dialkylcarbamato complexes [Fe(II)(O2CNR2)2] n (R=Et, n =6, 1; R= i Pr, 2) and [Fe(II)8(μ4-O)2(O2CNiPr2)12], 3, by dioxygen were carried out both in an anhydrous hydrocarbon and in the solid state affording [Fe(III)2(O)(O2CNR2)4] x , 7 and 8 for R=Et and i Pr, respectively, and [Fe(III)4(O)3(O2CNiPr2)6] y , 9. The stoichiometric O2 uptake was not accompanied by oxidation of the ligand. Recovery of unchanged starting material was observed when the manganese(II) derivatives [Mn(II)(O2CNR2)2] n (R=Et, n =6, 4; R= i Pr, 5) were treated with O2. Nevertheless, when [Mn(II)8(μ4-O)2(O2CNiPr2)12], 6, prepared in situ by reaction of 5 with water (Mn/H2O molar ratio=4), was reacted with O2, complete oxidation occurred to a product where manganese showed an average oxidation number III, [Mn(III)4(O)3(O2CN i Pr2)6] y , 10. The product [Mn(II)6Mn(III)2(μ4-O)2(μ3-O)(O2CN i Pr2)12], 11, obtained by partial oxidation of 6 by O2, has been characterised by X-ray diffraction methods. [Copyright &y& Elsevier]

Neutral complexes with generic formula [PtCl 2 (PPh 3 )(L)] were efficiently oxidized to [PtCl 4 (PPh 3 )(L)] (L = dibenzylamine, p -toluidine, diethanolamine, pyridine and acetonitrile) using PhICl 2 The anionic complex [TBA][PtCl 3 (PPh 3 )] (TBA = Tetrabutylammonium) was also oxidized to [TBA][PtCl 5 (PPh 3 )] with this method. The obtained products were fully characterized by 1 H, 13 C, 31 P and 195 Pt NMR, IR-ATR spectroscopy, elemental analysis and, for complexes cis -([PtCl 4 (PPh 3 )( p -toluidine)]·CHCl 3 and trans -[PtCl 4 (PPh 3 )(NCCH 3 )]·CH 3 CN, also by single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The reactions are reported of NbX 5 (X = Cl, Br), TiCl 4 and Ti(O i Pr) 4 with a selection of carboxylic acids exhibiting a known biological role, in a chlorinated solvent. The reactions of NbX 5 with acetylsalicylic acid (aspirin) proceeded with selective deacetylation of the organic reactant and formation of the salicylate complexes NbX 4 (C 7 H 5 O 3 ) ( 1a , X = Cl; 1b , X = Br) in 60–65% yields. NbCl 5 reacted with diclofenac and ethacrynic acid (EA-CO 2 H) to give NbCl 3 [κ 3 O,O,N -O 2 CCH 2 (C 6 H 4 )NC 6 H 3 Cl 2 ], 2 (80% yield), and NbCl 4 (O 2 C-EA), 3 (72% yield), respectively. Ti(O i Pr) 4 reacted with ethacrynic acid giving Ti(O i Pr) 2 (O 2 C-EA) 2 , 4 , in 74% yield, as a mixture of two isomers. All the products were characterized by means of analytical and spectroscopic methods, moreover DFT studies were carried out to give insight into structural features. [ABSTRACT FROM AUTHOR]

The simple but rarely used heterotopic divergent ligand N-oxide-4,4′-bipyridine (bipyMO) has been exploited, for the first time, for the preparation of heterometallic derivatives, showing the ability to selectively use its two potential coordination sites in dependence of the metal ion nature. By reacting in refluxing acetonitrile ∞ 1 [Cu(hfac) 2 (bipyMO)] with ∞ 1 [Mn(hfac) 2 (bipyMO)] (herein completely characterized), the heterometallic self-assembled monodimensional coordination polymer containing the two regularly alternated moieties Cu(hfac) 2 [N] 2 and Mn(hfac) 2 [O] 2 was obtained in high yield and purity and structurally characterized. On the other hand, a molecular heterometallic compound was obtained using, as a ligand, the here prepared mononuclear complex trans -[PtCl 2 (bipyMO)(PPh 3 )], with the hypodentate bipyMO ligand coordinated to platinum through the nitrogen atom. Reaction with [Zn(hfac) 2 (DME)] afforded the heterometallic trinuclear complex trans [Zn(hfac) 2 { trans -PtCl 2 (PPh 3 )(bipyMO)} 2 ] that was structurally characterized. [ABSTRACT FROM AUTHOR]

Exhaustive hydrolysis of a mixture of [La 4 (CO 3 )(O 2 CNBu 2 ) 10 ] and [Cu(O 2 CNBu 2 )(py ∗ ) 2 ] (py ∗ = 4-dimethylamino pyridine) in molar ratio 1/2 corresponding to a La/Cu molar ratio 2/1 was carried out in toluene at room temperature. The carbamato derivatives of lanthanum and copper can be easily prepared by extraction of the metal ions from aqueous solution into heptane by the NHBu 2 /CO 2 system, according to a method previously reported. The copper precursor was selected amongst a number of derivatives in respect of its easy tractability. The tetragonal modification T′ of La 2 CuO 4 was obtained by treatment at 600 °C of the intermediate mixed carbonate. The thermal treatment of T′-La 2 CuO 4 at 850 °C, followed by cooling down to room temperature, afforded the orthorhombic modification of the mixed oxide. [ABSTRACT FROM AUTHOR]

Dinuclear platinum(II) complexes [{PtCl 2 (PPh 3 )} 2 (μ-N–N)], where N–N is a divergent bidentate nitrogen ligand, were prepared by reacting cis -[PtCl 2 (PPh 3 )(NCMe)] with N–N in a Pt/N–N molar ratio 2. The ( trans , trans )-isomers were obtained as kinetic products and recovered in good yields and high purity { 1 , N–N = pyrazine (pyrz); 2 , N–N = 4,4′-bipyridyl (bipy); 3 , N–N = piperazine (pipz); 4 , N–N = p-xylylendiamine (xylN 2 )}. Cis -[PtCl 2 (PPh 3 )(NCMe)] was also reacted with the tridentate divergent ligand 2,4,6-tris-(pyrid-4′-yl)1,3,5-triazine (py3TRIA) in molar ratio 3 with formation of the trinuclear ( trans , trans , trans )-[{PtCl 2 (PPh 3 )} 3 (μ-py3TRIA)], 5 . On the other hand, the treatment of cis -[PtCl 2 (PPh 3 )(NCMe)] with the monodentate pyridine (py) produced a mixture of both trans -[PtCl 2 (PPh 3 )(py)] ( 6a ) and cis -[PtCl 2 (PPh 3 )(py)] ( 6b ). The reactions of cis -[PtCl 2 (PPh 3 )(NCMe)] with N–N = pyrz, bipy, pipz, carried out with a Pt/N–N molar ratio 1, were monitored by 31 P NMR spectroscopy. Equilibria were observed in solution, involving dinuclear ( trans – trans )-[{PtCl 2 (PPh 3 )} 2 (μ-N–N)], mononuclear [PtCl 2 (PPh 3 )(N–N)] and free N–N. The addition of an excess of the divergent ligand allowed the complete conversion to the corresponding mononuclear complexes. With the heteroaromatic ligands both geometric isomers were observed ( 7a , 7b and 8a , 8b , for pyrz and bipy derivatives, respectively) while with pipz the trans -isomer only was detected, 9 . In the system involving bipy, the scarcely soluble dinuclear ( cis , cis )-[{PtCl 2 (PPh 3 )} 2 (μ-bipy)], 2b , was also obtained. Products 2 , 2b , 3 ·2(CHCl 3 ) and 6a ·0.5(C 2 H 4 Cl 2 ) were structurally characterized by single crystal X-ray diffraction methods. [ABSTRACT FROM AUTHOR]

The coordination polymers [ Ln ( β - dik ) 3 bpy ] ∞ 1 ·C 7 H 8 (Ln = Eu, β-dik = dbm, tta, hfac; Ln = Tb; β-dik = dbm; Hdbm = dibenzoylmethane, Htta = thenoyltrifluoroacetone, Hhfac: hexafluoroacetylacetone) were easily assembled in mild conditions and high yields starting from the anhydrous lanthanide β-diketonates as nodes and 4,4′-bipyridine (bpy) as connector. X-ray single crystal studies have shown zigzag extended chains where lanthanide centres are 8-coordinated in a distorted square-antiprismatic geometry. Photoluminescence studies show bright red europium emission and spectral features dependent on the topology of the polymeric chains. [ABSTRACT FROM AUTHOR]

The ring opening polymerization reaction of tetrahydrofuran (thf) by WCl 6 was investigated under different conditions, and the polymeric material was characterized by NMR and SEC (Size Exclusion Chromatography) analyses. The mixed valence complex [(thf) 2 (μ-H)][{WOCl 3 (thf)} 2 (μ-O)], 3 , was isolated from the reactions of WCl 6 with 4–8 equivalents of thf in dichloromethane at room temperature, and crystallographically characterized. The formation of 3 was preceded by that of WOCl 4 (thf), 2 , while Cl(CH 2 ) 4 Cl and Cl(CH 2 ) 4 O(CH 2 ) 4 Cl were identified as the prevalent organic side products. The 1:1 M reaction of WCl 6 with MeO(CH 2 ) 2 OH, in CH 2 Cl 2 at room temperature, afforded the complexes (WOCl 4 ) 2 (μ-κ 2 -1,4-dioxane), 4 , and WCl 5 (OCH 2 CH 2 OMe), 5 , in admixture with Cl(CH 2 ) 2 Cl, MeO(CH 2 ) 2 OMe and MeCl. Also complex 4 , resulting from a C O bond forming process, was characterized by X-ray crystallography. [ABSTRACT FROM AUTHOR]

Partial hydrolysis (H 2 O/Ln molar ratio = ¼) of lanthanum di- iso -propylcarbamato complex, [La(O 2 CN i Pr 2 ) 3 ], 1 , afforded the tetranuclear μ-oxo derivative [La 4 O(O 2 CN i Pr 2 ) 10 ], 2 , which was structurally characterized by single crystal X-ray diffraction studies. The carbonato–carbamato derivative of lanthanum, [La 4 (CO 3 )(O 2 CNBu 2 ) 10 ], 3 , was prepared by extraction of lanthanum ions from aqueous solution into heptane by the NHBu 2 /CO 2 system. Partial hydrolysis (H 2 O/Ln molar ratio = ½) of N , N -di-iso-propylcarbamato complexes of neodymium, europium, gadolinium and terbium, [Ln(O 2 CN i Pr 2 ) 3 ], yielded the derivatives [Ln 2 (CO 3 )(O 2 CN i Pr 2 ) 4 ] (Ln = Nd, 4 , Eu, 5 , Gd, 6 ). Exhaustive hydrolysis of [Ln(O 2 CNR 2 ) 3 ] (Ln = Nd, Tb, R = Bu; Ln = Eu, Gd, R = i Pr, Bu) produced hydrated lanthanide carbonates, Ln 2 (CO 3 ) 3 · n H 2 O. For sake of comparison with a block d metal, the exhaustive hydrolysis of two copper(II) carbamato complexes, [Cu(O 2 CNEt 2 ) 2 (NHEt 2 )] 2 and [Cu(O 2 CN i Pr 2 ) 2 ], was carried out with formation in both cases of the hydrated basic carbonate Cu 2 (OH) 2 (CO 3 )· n H 2 O. The exhaustive hydrolysis of mixtures of cerium and lanthanum or cerium and terbium N , N -dibutylcarbamato complexes allowed the preparation of mixed oxides containing the two metals in the desired molar ratio, via the intermediate formation of the corresponding mixed carbonates. [ABSTRACT FROM AUTHOR]

Nanostructured ceria has been prepared in mild conditions by hydrolysis of the N , N -dibutylcarbamato complex of cerium(III), [Ce(O 2 CNBu 2 ) 3 ], obtained by lanthanide extraction from aqueous solution into heptane containing CO 2 saturated NHBu 2 . In dependence of the hydrolysis conditions, cerium(III) carbonates or hydroxocarbonate (characterized by IR, XRD and metal content) were obtained. Thermal treatment of these products at relatively low temperature (200 °C) yielded CeO 2 in the form of a light yellow powder. The structure and morphology of the samples were studied by TEM, FESEM and XRD studies. The medium crystallite dimensions, estimated by TEM, appear to be of a few nanometers. Ceria with smaller medium crystallite dimensions was obtained by increasing the amine concentration in the course of the hydrolysis process. [ABSTRACT FROM AUTHOR]

A series of neutral complexes of platinum(II) of general formula [PtCl 2 L(PPh 3 )] [L = Et 2 NC(Me)NH, SOMe 2 , CO, Et 2 NH, (HOCH 2 CH 2 ) 2 NH, Bz 2 NH, N-morpholine] was prepared starting from suitable precursors. The syntheses and spectroscopic characterizations of the two new complexes trans -[PtCl 2 (N-morpholine)(PPh 3 )] and cis -[PtCl 2 (SOMe 2 )(PPh 3 )] are described as well as their X-ray structures. The antiproliferative activity of all the available compounds was tested in vitro against HeLa, H460 and A549 human tumor cell lines. A brief discussion regarding the structure–activity correlation is presented. [ABSTRACT FROM AUTHOR]

Neodymium and terbium pentafluorophenolates, containing 1,10-phenanthroline as ancillary ligand, [Ln(OC 6 F 5 ) 3 (phen) 3 ], ( 1 Ln = Nd, 2 Ln = Tb) have been synthesized by reacting the N , N -dibutylcarbamato complexes, [Ln(O 2 CNBu 2 ) 3 ], easily obtained from aqueous solutions of lanthanide salts, with C 6 F 5 OH in the presence of 1,10-phenanthroline. The formation of the sparingly soluble hydrated compound [Tb(OC 6 F 5 ) 3 (phen) 2 (H 2 O)·phen], 3 , was observed, due to fortuitous presence of water. Single crystal X-ray diffraction studies on compounds 1 , 3 and 3 ·DME (DME = dimethoxyethane) showed coordination numbers (CN) 9 for neodymium in 1 and 8 for terbium in 3 and 3 ·DME, where only two 1,10-phenanthroline ligands are coordinated to terbium, the third forming two hydrogen bonds with the coordinated water. The structural characterisation of [NH 2 Bu 2 ][C 6 F 5 O], 4 , showed the organisation of the product in ionic quartets. The photoluminescence spectra of 1 and 2 displayed the typical emissions related to the lanthanide centre in the NIR and visible region, respectively. [ABSTRACT FROM AUTHOR]

A comprehensive survey of the syntheses and of spectroscopic, analytical and structural data of silver(I), copper(I), and copper(II) complexes containing scorpionate and related ligands and prepared by this group has been reported. This review outlines the possible strategies that can be used in this field for the synthesis of analogous complexes. Statistical analyses of structural features are reported as a function of (1) the steric and electronic properties of the scorpionate ligand, (2) the steric and electronic properties of eventual ancillary ligands, and (3) the nature of the counter-ion. The most important results obtained in this field have been also summarized. [Copyright &y& Elsevier]