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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]

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]

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]