Diastereomerically Pure Heterodi- and Heterotetrametallic (Pd and Pt) Compounds: A Study of the Effect Induced by the Binding Mode of a Ferrocene-Containing Ligand on Their Electrochemical Properties.

The reaction of (1S,2R)-[(η5-C5H5)Fe{(η5-C5H4)-CH=NCH(Me)-CH(OH)(C6H5)}] (1) with Na2[PdCl4] in the presence of Na(OAc)·3H2O produced three diastereomerically pure tetrametallic cyclopalladated complexes (6bI-6bIII). In two of them (6bI and 6bII), the imine 1 adopts the [C(sp2,ferrocene), N]- mode of binding, but they differ in the planar chirality of the 1,2-ferrocenyl unit (Sp in 6bI and Rp in 6bII), whereas ligand 1 in 6bIII acts as a [C(sp2,phenyl),N]- group. Treatment of 6bI-6bIII with PPh3 gave [Pd{κ2-C,N{(η5-C5H3)-CH=N-CH(Me)-CH(OH)(C6H5)}Fe(η5-C5H5)}Cl(PPh3)] (7bI,7bII) and [Pd{κ2-C,N{(C6H4)-CH(OH)-CH(Me)-N=CH-(η5-C5H4)}Fe(η5-C5H5)}Cl(PPh3)] (7bIII). The PtII compounds [Pt{κ2-C,N{(η5-C5H3)-CH=NCH(Me)CH(OH)(C6H5)}Fe(η5-C5H5)}Cl(PPh3)] [(Sp,1S,2R) and (Rp,1S,2R) diastereomers, 7aII and 7aII, respectively)] have also been prepared. The results of electrochemical studies of 6bI-6bIII, 7bI-7bIII, 7aI, 7aII and related PtII complexes with 1 acting as an (N) or (N,O)- ligand are also reported. Comparison of the results provides conclusive evidence for the relative influence of the mode of binding of the ligand, the nature of the MII atom, the type of metallated atom C(sp2,phenyl or ferrocenyl), the ancillary ligands and their relative disposition on the electrochemical properties of this type of compound

Comparison of the thermal decomposition processes of several aminoalcohol-based ZnO inks with one containing ethanolamine

Four inks for the production of ZnO semiconducting films have been prepared with zinc acetate dihy-drate as precursor salt and one among the following aminoalcohols: aminopropanol (APr), aminomethylbutanol (AMB), aminophenol (APh) and aminobenzyl alcohol (AB) as stabilizing agent. Their thermaldecomposition process has been analyzed in situ by thermogravimetric analysis (TGA), differential scan-ning calorimetry (DSC) and evolved gas analysis (EGA), whereas the solid product has been analysedex-situ by X-ray diffraction (XRD) and infrared spectroscopy (IR). Although, except for the APh ink, crys-talline ZnO is already obtained at 300◦C, the films contain an organic residue that evolves at highertemperature in the form of a large variety of nitrogen-containing cyclic compounds. The results indicatethat APr can be a better stabilizing agent than ethanolamine (EA). It gives larger ZnO crystal sizes withsimilar carbon content. However, a common drawback of all the amino stabilizers (EA included) is thatnitrogen atoms have not been completely removed from the ZnO film at the highest temperature of ourexperiments (600◦C)

Platinum(II) and palladium(II) complexes derived from 1-ferrocenylmethyl-3,5-diphenylpyrazole. Coordination, cyclometallation or transannulation?

The synthesis and characterization of the novel pyrazole derivative [1-(Fc-CH2)-3,5-Ph-2-(C3HN2)] (2) {Fc = (eta(5) -C5H5)Fe(eta(5)-C5H4)-} with a ferrocenylmethyl substituent on position 1 of the heterocycle is described. The study of the reactivity of 2 with cis-[MCl2L2] (M = Pt and L = dmso or M = Pd and L = dmso or CH3CN), Pd(AcO)(2) or Na-2[PdCl4] under different experimental conditions, has allowed us to isolate and characterize a wide variety of platinum(II) or palladium(II) complexes: trans-[Pt{1-(Fc-CH2)-3,5-Ph2-(C3HN2)} Cl-2(dmso)] (3), the cis-isomers of [M{1-(Fc-CH2)-3,5-Ph-2-(C3HN2)}Cl-2(dmso)] {M = Pt (4) or Pd (7)}, trans-[Pd{1-(Fc-CH2)-3,5-Ph-2-(C3HN2)}(2)Cl-2] (8), the cyclometallated compounds [M{1-(Fc-CH2)-(3-C6H4)-5-Ph-(C3HN2)}Cl(L)] {with M = Pt and L = dmso (5) or PPh3 (6) or M = Pd and L = PPh3 (9)} and the palladium(II) complex [Pd{1-[(eta(5)-C5H4)Fe{(eta(5)-C5H4)-CH2]-3,5-Ph-2-(C3HN2)}Cl(PPh3)] (10) that arises from a transannulation process. The crystal structures of the free ligand 2 and compounds 4, 7, 9 and 10 are also reported and confirm the cis-disposition of the Cl- ligands in 4 and 7, the trans-arrangement of the phosphorous and the nitrogen atoms in 9 and 10, the mode of binding of the ligand in 4, 7, 9 and 10 and the nature of the metallated carbon atom {C(sp(2), phenyl) in 9 or the C(sp(2), ferrocenyl) of the C5H5 ring in 10}. In order to rationalize the different nature of the products isolated in the reactions of 2 with Pd(AcO)(2) or Na-2[PdCl4] and NaAcO density functional theory (DFT) calculations of the complexes have also been carried out

Study of a sol-gel precursor and its evolution towards ZnO

The processes involved in the assembly of zinc acetate dihydrate {Zn(CH3COO)2·2H2O} and ethanolamine (H2NCH2CH2OH), with or without 2-methoxyethanol as solvent, have been analysed by infrared spectra, mass spectrometry, nuclear magnetic resonance, powder X-ray diffraction and computational studies. Thermal evolution of the mixtures was characterized by thermoanalytical and structural techniques (thermogravimetry, differential thermal analysis, differential scanning calorimetry, X-ray diffraction and X-Ray photoelectron spectroscopy). Computational studies together with experiments served to thoroughly describe the precursor and its decomposition. The thermal decomposition of the mixture and its transformation into crystalline ZnO take place in a temperature range between 50 and 450 °C through different processes. With solvent, the processes need temperatures 90 oC higher with respect to the mixture without solvent, and ZnO arises at 250 ºC

Role of Ethanolamine on the Stability of a Sol-Gel ZnO ink

This work presents a detailed structural and chemical characterization of the system formed by zinc acetate dihydrate (ZAD) and ethanolamine (EA) with methoxyethanol (ME), in order to describe its stability. The origin of the mixture degradation during storage at room conditions is analyzed. Complementary computational (or theoretical) DFT calculations on the precursor formed in this reaction in ME and those of EA (free or in the same solvent) and in the presence or absence of CO2, light or both simultaneously are also reported in order to clarify the relative weight of these factors in the degradation process. In all cases, the models were tested as potential energy minimum and their photo-absorption spectra were simulated. The calculations show that the monomeric species formed in this process tend to assembly into dimers, which are more photosensitive and reactive than the monomer. Our results explain the experimental observations and provide a better understanding of the role played by EA, ME and CO2 in the formation of ZnO and, consequently, allow optimizing the technological processes to prepare these films

A New Cyclometalation Motif: Synthesis, Characterization, Structures, and Reactivity of Pallada- and Platinacycles with a Bidentate {C(sp2,cyrhetrene),N}− Ligand

The synthesis, characterization, X-ray crystal structure, and study of the reactivity of the novel cyretrenyl ligand [{(η5-C5H4-2-C5H4N)}Re(CO)3 (1) with Pd(OAc)2 or [MCl2(DMSO)2] (M = Pd, Pt) are reported. These studies have allowed us to obtain the bis-μ-ligand cyclopalladated complexes [Pd{[k2-C,N-(η5-C5H3)-2(C5H4N)]Re(CO)3)}(μ-X)]2 (X = OAc (2a), Cl (4a)) and monomeric pallada- and platinacycles of the general formula [M{[k2-C,N-(η5-C5H3)-2(C5H4N)]Re- (CO)3}(X)(L)] (M = Pd, L = PPh3, X = OAc (3a), Cl (5a); M = Pd, L = DMSO, X = Cl (6a); M = Pt, X = Cl, L = PPh3 (5b), DMSO (6b)), where compound 1 acts as a {C(sp2,cyrhetrene),N} bidentate ligand. All complexes were characterized by elemental analyses, infrared spectroscopy, and one- and twodimensional NMR. The X-ray crystal structures of 5a 3 1/2CH2Cl2, 5b, 6a 3CH2Cl2, and 6b confirm (a) the existence of the five-membered metallacycle, (b) the {C(sp2,cyrhetrene),N} mode of binding of the metallo ligand 1, and (c) the cis arrangement between the metalated carbon and the neutral L ligands (PPh3 or DMSO) in these products. A comparative study of the structures, spectroscopic properties, and reactivities of the new cyclometalated compounds and those of their analogues with a bidentate {C(sp2,ferrocene),N} ligand is also reported

Heterodi- (Fe, Pd/Pt) and heterotrimetallic (Fe2, Pd) complexes derived from 4-(ferrocenylmethyl)-N-(2-methoxyethyl)-3,5-diphenylpyrazole as potential antitumoral agents

The study of the reactivity of the pyrazole derivative 1-[MeO-(CH2)2]-3,5-Ph2-4-(CH2Fc) (C3N2) (1, Fc = ferrocenyl) with Na2[PdCl4], Pd(OAc)2, and [MCl2(dmso)2] (M = Pd or Pt,dmso = dimethyl sulfoxide) has allowed us to isolate trans-[Pd{κ-N-(1-{MeO(CH2)2}-3,5-Ph2-4-{CH2Fc} {C3N2})}2Cl2] (2), [Pd{κ2-C,N(1-{MeO(CH2)2}-3-{C6H4}-5-Ph-{C3N2})}{κ-N-(1-{MeO(CH2)2}-3,5-Ph2-4-{CH2Fc} {C3N2})}Cl] (3), [Pd{κ2-C,N(1-{MeO(CH2)2}-3-{C6H4}-4-{CH2Fc}-5-Ph-{C3N2})}Cl-(PPh3)] (4), and the trans (5) and cis (6) isomers of [Pt{κ-N-(1-{MeO(CH2)2}-3,5-Ph24-{CH2Fc} {C3N2})}Cl2(dmso)]. Compound 1 acts as a N (in 2, 5, and 6) or (C,N) donor ligand (in 4) and shows both binding modes in 3. The cytotoxic assessment of 1 6 against MCF7, MDA-MB231 (breast), and HCT-116 (colon) cancer cell lines reveal that (1) 1 is more potent than 1-[MeO(CH2)2]-3,5-Ph2-(C3HN2) (V), (2) 2 6 have cytotoxic activity, (3) 2 and 3 are less active than 4 6, and (4) 6 is the most potent compound against the three cancer cell lines

Experimental and Theoretical Studies of the Factors Affecting the Cycloplatination of the Chiral Ferrocenylaldimine (SC)-[(η5-C5H5)Fe{(η5-C5H4) C(H)=N CH(Me)(C6H5)}]

The study of the reactivity of the enantiopure ferrocenyl Schiff base (SC)-[FcCH=N CH(Me)(C6H5)] (1) (Fc = (η5-C5H5)Fe(η5-C5H4)) with cis-[PtCl2(dmso)2] under different experimental conditions is reported. Four different types of chiral Pt(II) have been isolated and characterized. One of them is the enantiomerically pure trans-(SC)-[Pt{κ1-N[FcCH=N CH(Me)(C6H5)]}Cl2(dmso)] (2a) in which the imine acts as a neutral N-donor ligand; while the other three are the cycloplatinated complexes: [Pt{κ2-C,N [(C6H4) N=CHFc]}Cl(dmso)] (7a) and the two diastereomers {(Sp,SC) and (Rp,SC)} of [Pt{κ2-C,N[(η5-C5H3) CH=N {CH(Me)(C6H5)}]Fe(η5-C5H5)}Cl(dmso)] (8a and 9a, respectively). Isomers 7a-9a, differ in the nature of the metallated carbon atom [CPh (in 7a) or CFc (in 8a and 9a)] or the planar chirality of the 1,2-disubstituted ferrocenyl unit (8a and 9a). Reactions of 7a 9a with PPh3 gave [Pt{κ2-C,N[(C6H4) N=CHFc]}Cl(PPh3)] (in 7b) and the diastereomers (Sp,SC) and (Rp,SC) of [Pt{κ2-C,N[(η5-C5H3) CH=N {CH(Me)(C6H5)}] Fe(η5-C5H5)}Cl(PPh3)] (8b and 9b, respectively). Comparative studies of the electrochemical properties and cytotoxic activities on MCF7 and MDA-MB231 breast cancer cell lines of 2a and cycloplatinated complexes 7b-9b are also reported. Theoretical studies based on DFT calculations have also been carried out in order to rationalize the results obtained from the cycloplatination of 1, the stability of the Pt(II) complexes and their electrochemical properties

Pd(II) complexes with N-substituted pyrazoles as ligands. The influence of the R group [OMe versus NMe2] of [1-{R(CH2)2}-3,5-Ph2(C3HN2)] on their cytotoxic activity on breast cancer cell lines

The study of the reactivity of the novel pyrazole derivative [1-{MeOe(CH2)2e}-3,5-Ph2e(C3HN2)] (1) with Na2[PdCl4] or Pd(OAc)2 under different experimental conditions has allowed us to isolate and characterize the trans-isomers of [Pd{[1-{MeOe(CH2)2e}-3,5-Ph2e(C3HN2)]}2(X)2] [X ¼ Cl (2) or OAc (3)] and the di-m-ligand bridged cyclopalladated complexes [Pd{k2,C,N[1-{MeOe(CH2)2e}-3-(C6H4),5-Ph- (C3HN2)]}(m-X)]2 [X ¼ OAc (4) or Cl (5)]. Further treatment of compounds 4 or 5 with PPh3 in CH2Cl2 produced the bridge splitting and the formation of [Pd{k2,C,N[1-{MeOe(CH2)2e}-3-(C6H4),5-Ph- (C3HN2)]}X(PPh3)] [X ¼ OAc (6) or Cl (7)]. The cytotoxic assessment of the free ligand (1) and the Pd(II) complexes on the two breast cancer cell lines MCF7 and MDA-MB231 reveals that: a) compound 1 is less active than its analogue [1-{Me2Ne(CH2)2e}-3,5-Ph2e(C3HN2)] (Ic) and b) palladacycles 4e7 showed a remarkable cytotoxic activity in the MDA-MB231 cell line (with IC50 values in the range 9.1e14.4 mM)

Influence of the Nature of Aminoalcohol on ZnO Films Formed by Sol-Gel Methods

Here we present comparative studies of: (i) the formation of ZnO thin films via the sol-gel method using zinc acetate dihydrate (ZAD), 2-methoxyethanol (ME) as solvent, and the aminoalcohols (AA): ethanolamine, (S)-(+)-2-amino-1-propanol, (S)-(+)-2-amino-3-methyl-1-butanol, 2-aminophenol, and aminobenzyl alcohol, and (ii) elemental analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy, absorption and emission spectra of films obtained after deposition by drop coating on glass surface, and thermal treatments at 300, 400, 500 and 600 ◦C. The results obtained provide conclusive evidences of the influence of the AA used (aliphatic vs. aromatic) on the ink stability (prior to deposition), and on the composition, structures, morphologies, and properties of films after calcination, in particular, those due to the different substituents, H, Me, or iPr, and to the presence or the absence of a -CH2- unit. Aliphatic films, more stable and purer than aromatic ones, contained the ZnO wurtzite form for all annealing temperatures, while the cubic sphalerite (zinc-blende) form was also detected after using aromatic AAs. Films having frayed fibers or quartered layers or uniform yarns evolved to 'neuron-like' patterns. UV and photoluminescence studies revealed that these AAs also affect the optical band gap, the structural defects, and photo-optical properties of the films