pinecone/core-2020-05-10-deduplication huggingface dataset:
A Binuclear Copper(II) Complex Containing the Pyrazine-2,5-dicarboxylate Ligand: Study of the Magnetic Exchange through the Pyrazine Bridge

Disponible en: http://www.xtal.iqfr.csic.es/publications/eur-inorg2005.pdfThe compound [Cu2(μ-pzdc)(phen)4](NO3)2·10H2O (1; pzdc =\ud
pyrazine-2,5-dicarboxylato; phen = 1,10-phenanthroline) has\ud
been structurally and magnetically characterised. Theoretical\ud
calculations have allowed us to establish a plausible magneto-structural correlation for pyrazine-bridged complexes.This work was supported by the Spanish Ministerio de Ciencia y\ud
Tecnología (MAT2002–03166) and the Universidad del País Vasco/\ud
Euskal Herriko Unibertsitatea (9/UPV 00169.310-15329-2003). G.\ud
B. thanks to the Eusko Jaurlaritza/Gobierno Vasco for a doctoral\ud
fellowship.Peer reviewe
Zirconium and hafnium complexes with (allylsilyl)(η-amidosilyl)-η5-cyclopentadienyl ligands: synthesis, structure and reactivity

The disubstituted cyclopentadiene C5H4(SiMe2Cl)[SiMe2(CH2CH=CH2)] was isolated by reaction of the lithium salt [Li{C5H4SiMe2(CH2CH=CH2)}] with SiMe2Cl2. It was then treated with NH2tBu and LiNH(2,6-Me2C6H3) to give the (aminosilyl)cyclopentadienes C5H4[SiMe2(CH2CH=CH2)][SiMe2(NHR)], which were further deprotonated to their dilithium salts [Li2{1-SiMe2NR-3-SiMe2(CH2CH=CH2)C5H3}] (R = tBu, 2,6-Me2C6H3). Reactions of the metal halides ZrCl4(THF)2 and HfCl4 with these dilithium salts, followed by alkylation of the resulting dichloro complexes, afforded the (η1-amidosilyl)-η5-cyclopentadienyl complexes [M{η5-C5H3(SiMe2-η1-NR)[SiMe2(CH2CH=CH2)]}X2] (R = tBu, 2,6-Me2C6H3; X = Cl, Me, CH2Ph; M = Zr, Hf). Only the bis(iminoacyl) complexes [M{η5-C5H3(SiMe2-η1-NtBu)[SiMe2(CH2CH=CH2)]}{η2-CR=N(2,6-Me2C6H3)}2] (M = Zr, Hf; R = Me, CH2Ph) could be isolated when the dialkylzirconium and -hafnium complexes were treated with CN(2,6-Me2C6H3); these were slowly transformed into the C–C-coupled diazametallacyclopentene compounds [M{η5-C5H3(SiMe2-η1-NtBu)[SiMe2(CH2CH=CH2)]}{η1-N(2,6-Me2C6H3)-CR=CR-η1-N(2,6-Me2C6H3)}] (R = Me, CH2Ph, M = Zr; R = Me, M = Hf) when their toluene solutions were heated to 70 °C–80 °C for long periods (2–4 d). The structural characterisation of all of the new compounds is described and the molecular structure of the dimeric dichlorozirconocene [ZrCl(μ-Cl){η5-C5H3(SiMe2-η1-NtBu)[SiMe2(CH2CH=CH2)]}]2, was determined by X-ray diffraction methods. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005
Luminescent polyoxotungstoeuropate anion-pillared layered double hydroxides

Novel luminescent polyoxometalate anion-pillared layered
double hydroxides (LDHs) were prepared by aqueous ion exchange
of a Zn–Al LDH precursor in nitrate form with the
europium-containing polyoxotungstate anions [EuW10O36]9–,
[Eu(BW11O39)(H2O)3]6– and [Eu(PW11O39)2]11–. The host–
guest interaction has a strong influence on the nature of the
final intercalated species, as evidenced by elemental analy-
Introduction
Layered double hydroxides are an important class
of ionic lamellar solids with the general formula
[M2+
1–xM3+
x(OH)2](Am–)x/m·nH2O (M2+ = Mg2+, Zn2+,
Ni2+ etc., M3+ = Al3+, Cr3+, Ga3+ etc).[1] The positively
charged layers, containing divalent and trivalent cations in
octahedral positions, are separated by charge balancing
anions and water molecules. The water molecules are connected
to both the metal hydroxide layers and the interlayer
anions through extensive hydrogen bonding. A range of organic
or inorganic guests may be incorporated into LDHs
by either ion exchange, direct synthesis or hydrothermal reconstruction
of calcined precursors.[2,3] In particular, intercalation
chemistry has been explored with the aim of introducing
catalytically active sites and photo- and electroactive
species. Many different types of metal coordination compounds
and oxometalates have been immobilized in LDHs,
including phthalocyanines, cyanocomplexes, oxalate complexes
and polyoxometalates (POMs).[4]
The first report of LDHs containing polyoxometalates
concerned their use as exhaust gas and hydrocarbon conversion
catalysts.[5] Since then, a variety of iso- and heteropolyanions
with different nuclearities and structures (Keggin,
Dawson, Preyssler, Finke) have been incorporated into the
interlayer space of these materials.[6–18] Two factors assume
considerable importance for the successful intercalation of
polyoxometalates into an LDH compound. First, the heteropoly
species should carry sufficient charge in order to be
[a] Department of Chemistry, CICECO, University of Aveiro,
3810-193 Aveiro, Portugal
E-mail: helena@dq.ua.pt
[b] Department of Physics, CICECO, University of Aveiro,
3810-193 Aveiro, Portugal
© 2006 Wiley-VCH Verlag 726 GmbH & Co. KGaA, Weinheim Eur. J. Inorg. Chem. 2006, 726–734
sis, powder X-ray diffraction (XRD), infra-red (IR) and Raman
spectroscopy, solid state magic-angle spinning (MAS) 11B
and 31P NMR spectroscopy, and photoluminescence spectroscopy.FCT - POCT
η2-Iminoacyl and η2-acyl monocyclopentadienyl tantalum complexes bearing oxo and oxo-borane ligands

Alkyl-chloro ligand exchange by the reaction of [TaCp*R2{O·B(C6F5)3}] (R = CH2Ph, Me) with Ph3CCl gave the monoalkyl compounds [TaCp*RCl{O·B(C6F5)3}] (R = CH2Ph, Me). Insertion of CNAr (Ar = 2,6-Me2C6H3) and CO into a Ta–C bond of the mono- and dialkyl complexes gave the iminoacyl compounds [TaCp*X{η2-C(R)=NAr}{O·B(C6F5)3}] (X = R = CH2Ph, Me; X = Cl, R = CH2Ph) and the acyl compounds [TaCp*X{η2-C(R)=O}{O·B(C6F5)3}] (X = R = CH2Ph, Me; X = Cl, R = CH2Ph), respectively. The related chloro compound [TaCp*Cl{η2-C(Me)=NAr}{O·B(C6F5)3}] was isolated from the reaction of the oxo derivative [TaCp*Cl{η2-C(Me)=NAr}(O)] with the Lewis acid B(C6F5)3. Addition of CNAr or pyridine to [TaCp*(CH2Ph){η2-C(CH2Ph)=NAr}{O·B(C6F5)3}] afforded the borane-free complex [TaCp*(CH2Ph){η2-C(CH2Ph)=NAr}(O)] and the acid-base adduct L·B(C6F5)3 (L = py, CNAr). The molecular structures of [TaCp*Cl{η2-C(Me)=NAr}{O·B(C6F5)3}] and [TaCp*(CH2Ph){η2-C(CH2Ph)=O}{O·B(C6F5)3}] were obtained from X-ray diffraction studies
Ligand variations in ReX(diimine)(CO)(3)] complexes: Effects on photocatalytic CO2 reduction

Two series of complexes MX(diimine)(CO)(3)] (M = Tc, Re) have been prepared, fully characterised and investigated for their ability to act as photocatalysts for the reduction of CO2 to CO. One series consists of complexes with different aromatic diimine ligands while keeping X = Br- constant. The second series describes complexes with diimine = 2,2-bipyridine and variations in the anionic ligand X-. Although numerous complexes of this type have been prepared and investigated before, a systematic study of their photocatalytic activity has not yet been carried out. Electrochemical and spectroscopic characterisation of these complexes has been performed with the objective of better understanding their respective activity in the photocatalytic CO2 reduction. Despite various modifications, catalytic activity is retained for all compounds exhibiting fluorescence, including (TcCl)-Tc-99(bipy)(CO)(3)], whereas nonfluorescing compounds did not convert CO2 to CO. The correlation of catalytic activity and spectroscopic or electrochemical properties such as absorption or emission wavelengths, redox potentials or Stern-Volmer constants for the reductive quenching of the excited complexes is difficult. Nevertheless, the study emphasises the possibility to obtain ReX(CO)(3)(diimine)] complexes with a wide range of physicochemical properties by ligand variations and the great potential of compounds of this class of complexes as inorganic photosensitisers
Structures of the b- and d-acid derivatives of vitamin B-12 and their complexes with M(CO)(3)](+) (M=Tc-99m, Re)

The acid hydrolysis of natural vitamin B-12 yields several products in which the acetamide or propionamide side chains on the corrin framework are converted into the corresponding acids. These acids can be derivatised with further functionalities. We have separated in particular the b- and the d-acid derivatives 1 and 2, respectively, since functionalisation at these positions of the corrin ring generally keeps the affinity for vitamin B-12 transport proteins intact. Although the authenticity of I and 2 seemed evident from 1H NMR investigations, it has not been supported by X-ray structure analysis. The coupling of ethyl N-(3-aminopropyl)-N-(pyridin-2-ylmethyl)glycinate (3) to the carboxylate groups in 1 and 2 by peptide synthetic methods gave the vitamin B-12 derivatives 4 and 5, respectively. The structures of 4 and 5 could be characterised by X-ray analysis, which unambiguously confirmed the presence of the b- and d-acid in 1 and 2, respectively. The reaction of 4 and 5 with the complex Re(OH2)(3)(CO)(3)](+) in water gave the corresponding vitamin B12 derivatives 8 and 9, and the aqueous reaction of 4 and 5 with the complex Tc-99m(OH2)(3)(CO)(3)](+) afforded the Tc-99m homologues 10 and 11, respectively. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007
Synthesis, characterisation and luminescent properties of lanthanide-organic polymers with picolinic and glutaric acids

Three new lanthanide(III) complexes (Ln = Sm, Tb and Eu)
of picolinic and glutaric acid were prepared and characterised.
The crystal structure of the complex [Sm(glu)(pic)-
(H2O)2] (where Hpic and H2glu stand for picolinic and glutaric
acid, respectively) was determined by single-crystal Xray
diffraction. All the Ln complexes were characterised by
elemental analysis, infrared spectroscopy, X-ray powder diffraction
and thermoanalytical measurements. The combined
Introduction
The design of functional units from the molecular scale
to macroscopic assemblies has emerged as a new paradigm
in materials synthesis resulting in an interplay between conventional
molecular chemistry and conventional solid-state
science. This has been particularly clear in the development
of functional materials using coordination compounds such
as in the field of semiconductors technology, supramolecular
machinery, microporous and hybrid materials and catalysis.[
1] In some cases, the development of these functional
materials is based on the chemistry of well-known coordination
compounds as illustrated by the assembly of inorganic-
organic extended lattices[2] and in the thermolysis of
metal thiolato compounds to produce thin films or nanoparticles.[
3]
Metals coordinated to aromatic ambidentate ligands
form a class of compounds with a wide variety of coordination
modes which has long attracted the attention of chemists.[
4] Griffith and co-workers extended this type of chemistry
to the second row transition metals and, in particular,
[a] Department of Chemistry, University of Aveiro, CICECO,
3810-193 Aveiro, Portugal
Fax: +351-234-370-084
E-mail: ttrindade@dq.ua.pt
[b] Department of Physics, University of Aveiro, CICECO,
3810-193 Aveiro, Portugal
[c] Department of Chemistry, University of Cambridge,
Lensfield Road, CB2 1EW Cambridge, United Kingdom
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
© 2007 Wiley-VCH Verlag 4238 GmbH & Co. KGaA, Weinheim Eur. J. Inorg. Chem. 2007, 4238–4246
data show that these Ln complexes are isostructural. The effect
of both organic ligands on the photoluminescent behaviour
of the Sm3+, Eu3+ and Tb3+ complexes is discussed and
we anticipate the possibility of controlling the photoluminescence
of picolinic-containing lanthanide compounds by systematically
varying the length of the bridging ligand.FCT - POCI/QUI/58377/2004Grant - SFRH/BD/17968/2004Grant - SFRH/BPD/14954/ 200
Synthesis, characterization and X-ray structures of [α- diphenylethanedione bis(4-ethylthiosemicarbazonato)]palladium(II) and 1,2,4-triazine-3-thione-zinc(II) complexes obtained by metal-induced cyclization

This is the peer reviewed version of the following article: European Journal of Inorganic Chemistry 34 (2007): 5433-5438, which has been published in final form at  http://dx.doi.org/10.1002/ejic.200700619. This article may be used for non-commercial purposes in accordance With Wiley-VCH Terms and Conditions for self-archivingThe new cyclic 5-ethoxy-4-ethyl-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]- triazine-3-thione ligand (HTa3T-Et) has been obtained by an intramolecular cyclization reaction of α-diphenylethanedione bis(4- ethylthiosemicarbazone) (H2BbTSC-Et). The cyclization may be promoted either by hydroxylic solvents or by ZnII ions. Thus, the reaction of H2BbTSC-Et with ZnCl2 led to the formation of [Zn(HTa3T-Et)2Cl2] containing not the ligand H 2BbTSC-Et but the cyclic HTa3T-Et ligand that forms during the reaction. On the other hand, crystallization of H2BbTSC-Et from DMSO/EtOH produces a cocrystal containing the open-chain H2BbTSC-Et ligand together with the cyclic HTa3T-Et molecules, which are linked to a DMSO molecule by hydrogen bonds. However, reaction of the cocrystal with Pd II ions yields a planar tetracoordinate complex in which only the H2BbTSC-Et ligand, in the deprotonated form, is present. The preparation and molecular structures of these compounds are discussedWe are grateful to Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III (PI040354) of Spain for financial suppor
Liquid-Crystalline Ternary Rare-Earth Complexes

The thermal behavior of the metallomesogens [Ln(C12C16dbm)3(phen)], where Ln = La, Nd, Eu, Gd, Tb, Dy, Er, Yb; C12C16dbm = 1-(4-dodecyloxyphenyl)-3-(4-hexadecyloxyphenyl)-propane-1,3-dionate; phen = 1,10-phenanthroline) was investigated. The complexes of the light lanthanides (Ln = La, Nd) are not mesomorphic, whereas the complexes of the heavy lanthanides (Ln = Eu, Gd, Tb, Dy, Er, Yb) exhibit a monotropic smectic A phase. A model for the molecular organization of the molecules in the smectic A phase is proposed. The luminescence properties of the complexes [Eu(C12C16dbm)3(phen)], [Er(C12C16dbm)3(phen)] and [Yb(C12C16dbm)3(phen)] were investigated.status: publishe
Synthesis and reactivity of oxametallacyclic niobium compounds by using α,ß-unsaturated carbonyl ligands

Reduction of mono(cyclopentadienyl)niobium complexes\ud
[NbCpRCl4] [CpR = C5Me4H (1), C5H4SiMe2Cl (2),\ud
C5H4SiMe3 (3)] with Na/Hg in the presence of methyl methacrylate\ud
[MMA, CH2=C(Me)C(O)OMe (a)], methyl acrylate\ud
[MA, CH2=CHC(O)OMe (b)] and mesityl oxide [MO,\ud
CMe2=CHC(O)Me (c)] afforded the corresponding derivatives\ud
[NbCpRCl2(LL)] [CpR = C5Me4H, LL = MMA (1a); CpR\ud
= C5H4SiMe2Cl, LL = MMA (2a), MA (2b), MO (2c); CpR =\ud
C5H4SiMe3, LL = MMA (3a), MA (3b)] in variable yields depending\ud
on both the cyclopentadienyl and the ¿,ß-unsaturated\ud
carbonyl compounds. The reactivity of these complexes\ud
was studied toward protic and Lewis acids. Addition of triflic\ud
acid TfOH (Tf = CF3SO2) to 3b gave the triflate complex\ud
[NbCpRCl2{(CH2)2C(O)OMe}(OTf)] [CpR = C5H4SiMe3 (4)].\ud
The Lewis acids E(C6F5)3 (E = B, Al) reacted with complexes\ud
Introduction\ud
The bonding interaction of a butadiene ligand with a\ud
metal center is clearly dependent on the metal atom and\ud
may be formulated as a system containing a dianionic ligand\ud
for early high-valent transition metals or as a neutral\ud
ligand for low-valent late transition metals. However, the\ud
stability of the formal oxidation state of the metal atom and\ud
the nature of the ancillary substituents of both the complex\ud
and the diene ligand could play an important role in defining\ud
this interaction. Hence, complexes with this type of ligand\ud
are better represented with contributions from two\ud
main canonical forms, ¿2,¿-metallacyclic or ¿2-butadiene\ud
(Figure 1).[1¿5]\ud
[a] Departamento de Química Inorgánica, Universidad de Alcalá,\ud
Campus Universitario,\ud
28871 Alcalá de Henares (Madrid), Spain\ud
Fax: 34-91-885-4683\ud
E-mail: pascual.royo@uah.es\ud
[¿] X-ray diffraction studies\ud
Supporting information for this article is available on the\ud
WWW under http://www.eurjic.org/ or from the author.\ud
Eur. J. Inorg. Chem. 2008, 2313¿2320 © 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2313\ud
2b and 3b to give the three-membered metallacyclic (or ¿2-\ud
enone) compounds [NbCpRCl2{¿2-CH2=CHC(OMe){O·\ud
E(C6F5)3}}] [CpR = C5H4SiMe2Cl, E = B (5), Al (6); CpR =\ud
C5H4SiMe3, E = B (7), Al (8)], which decomposed to the corresponding\ud
adducts MA·E(C6F5)3. The same reaction with the\ud
2a and 3a derivatives only allowed the observation of the\ud
corresponding adducts MMA·E(C6F5)3. Complexes 2a,b and\ud
3a,b reacted with CO with elimination of the acrylate compounds,\ud
MA and MMA, respectively, to give the carbonylniobium(\ud
III) compounds [NbCpRCl2(CO)2]2 [CpR = C5H4Si-\ud
Me2Cl (9), C5H4SiMe3 (10)]. Analogous reactions with CNAr\ud
showed the elimination of the free MA and MMA compounds.We gratefully acknowledge the Ministerio de Educación y Ciencia\ud
(MEC) (project MAT2007-60997) and the Dirección General de\ud
Universidades e Investigación (DGUI) – Comunidad de Madrid\ud
(programme S-0505/PPQ-0328 COMAL-CM) (Spain) for financial\ud
support. R. A. A.-M. acknowledges MEC for a fellowship
Insight into cis-to-trans olefin isomerisation catalysed by group 4 and 6\ud
cyclopentadienyl compounds

Intramolecular isomerisation of the pendant allyl unit present in the model compound [MoH(η5-C5H4SiMe2CH2CH=CH2)(CO)3] reported before was investigated by DFT calculations. The coordination of CO and the splitting of the agostic Mo–H interactions found in metallacyclic transition states stabilise the cis and trans hydride compounds [MoH(η5-C5H4SiMe2CH=CHCH3)(CO)3] relative to the corresponding tricarbonyl molybdenum alkyl metallacycles. A comparison with an analogous zirconium system is included. To contrastthese results with the behaviour of metal hydride cyclopentadienyl compounds, which have no intramolecular alkene functionality, group 4 and 6 derivatives such as [Zr(η5-C5H4SiMe2-η1-NtBu)(η5-C5H4SiMe2CH2CH2-η1-CH2)] (2), [MH(η5-C5HMe4)(CO)3] [M = Mo (3), W (4)], and [ZrH(η5-C5H4SiMe2-η1-NtBu)(η5-C5H4R)] [R = H (5), SiMe3 (6)] were examined as selective catalysts for the intermolecular isomerisation of the terminal olefins allyltrimethylsilane (A) and 4-methyl-1-pentene (B). Zirconium hydride compounds were the most efficient catalysts. Compound 4 catalysed the same reaction but required heating at 140 °C, whereas compound 3 was inactive due to a dehydrogenation process, which produced the dinuclear compound [Mo(η5-C5HMe4)(CO)3]2 (7). Reaction of 4 and 5 with the internal alkenes trimethyl(1-propenyl)silane (C) and 4,4-dimethyl-2-pentene (D) favoured cis-to-trans isomer conversion with poor production of the corresponding terminal olefins
Synthesis, Characterization, and Oxygenation Studies of Carboxylate-Bridged Diiron(II) Complexes with Aromatic Substrates Tethered to Pyridine Ligands and the Formation of a Unique Trinuclear Complex

In this study, diiron(II) complexes were synthesized as small molecule mimics of the reduced active sites in the hydroxylase components of bacterial multicomponent monooxygenases (BMMs). Tethered aromatic substrates were introduced in the form of 2-phenoxypyridines, incorporating hydroxy and methoxy functionalities into windmill-type diiron(II) compounds [Fe[subscript 2](μ-O[subscript 2]CAr[superscript R])[subscript 2](O[subscript 2]CAr[superscript R])[subscript 2](L)[subscript 2]] (1–4), where[superscript –]O[subscript 2]CAr[superscript R] is a sterically encumbering carboxylate, 2,6-bis(4-fluorophenyl)-, or 2,6-bis(p-tolyl)benzoate (R = 4-FPh or Tol, respectively). The inability of 1–4 to hydroxylate the aromatic substrates was ascertained. Upon reaction with dioxygen, compounds 2 and 3 (L = 2-(m-MeOPhO)Py, 2-(p-MeOPhO)Py, respectively) decompose by a known bimolecular pathway to form mixed-valent diiron(II,III) species at low temperature. Use of 2-(pyridin-2-yloxy)phenol as the ligand L resulted in a doubly bridged diiron complex 4 and an unprecedented phenoxide-bridged triiron(II) complex 5 under slightly modified reaction conditions.National Institute of General Medical Sciences (U.S.) (Grant GM032134
Synthesis, Structure, and Spectroscopic Properties of the New Lanthanum(III) Fluoride Oxomolybdate(VI) La3FMo4O16

La3FMo4O16 crystallizes in the triclinic crystal system with space group P (1) over bar [a = 724.86(2) pm, b = 742.26(2) pm, c = 1469.59(3) pm, a = 101.683(2)degrees, beta 102.118(2)degrees, gamma = 100.279(2)degrees] with two formula units per unit cell. The three crystallographically independent La3+ cations show a coordination number of nine each, with one F- and eight O2- anions forming distorted monocapped square antiprisms. The fluoride anion is coordinated by all three lanthanum cations to form a nearly planar triangle. Besides three crystallographically independent tetrahedral [MoO4](2-) units, a fourth one with a higher coordination number (CN = 4 +1) can be found in the crystal structure, forming a dimeric entity with a formula of [Mo2O8](4-) consisting of two edge-connected square pyramids. Several spectroscopic measurements were performed on the title compound, such as infrared, Raman, and diffuse reflectance spectroscopy. Furthermore, La3FMo4O16 was investigated for its capacity to work as host material for doping with luminescent active cations, such as Ce3+ or Pr3+. Therefore, luminescence spectroscopic as well as EPR measurements were performed with doped samples of the title compound. Both the pure and the doped compounds can be synthesized by fusing La2O3, LaF3 and MoO3 (ratio 4:1:12; ca. 1 % CeF3 and PrF3 as dopant, respectively) in evacuated silica ampoules at 850 degrees C for 7 d.status: publishe
Spectroscopy of high-energy states of lanthanide ions

We discuss recent progress and future prospects for the analysis of the
4f${N-1}$5d excited states of lanthanide ions in host materials. Ab-initio
calculations for Ce$^{3+}$ in LiYF$_4$ are used to estimate crystal-field and
spin-orbit parameters for the 4f$^1$ and 5d$^1$ configurations. We discuss the
possibility of using excited-state absorption to probe the electronic and
geometric structure of the 4f$^{N-1}$5d excited states in more detail and we
illustrate these ideas with calculations for Yb$^{2+}$ ions in SrCl$_2$
Molybdenum complexes bearing thiophenic or- arylthiophenic groups : synthesis, electrochemical, spectroscopic and nonlinear optical properties

A series of complexes trans-[FMo(N=NCHL)(dppe)2][BF4] (L = (bi)thienyl or arylthienyl), were synthesized and fully characterized by 1H, 13C, 31P NMR, IR and UV–Vis spectroscopies. The electronic spectra and electrochemical behavior of the complexes were investigated. The electronic absorption spectra of these complexes display a broad low-energy band in the visible region attributable to metal-to ligand charge transfer (MLCT) transitions. The electron conjugated effect with the heterocyclic nucleus led to a notable improvement of visible light absorption and marked changes in the electrochemical behavior. The hyperpolarizabilities beta of the synthesized compounds were evaluated using the hyper-Rayleigh scattering technique.Fundação para a Ciência e a Tecnologia (FCT
Platinum complexes of aromatic selenolates

Several synthetic methods are used to prepare naphthalene-based aromatic 1,2-diselenoles. A new one-pot synthesis starting from naphthalene is used to produce theknown compound naphtho[1,8-c,d][1,2]diselenole (Se2naph).Friedel–Crafts alkylation is used on Se2naph to substitute either one tert-butyl group to form 2-tert-butylnaphtho[1,8-c,d][1,2]diselenole (mt-Se2naph) or two tert-butyl groups to form 2,7-di-tert-butylnaphtho[1,8-c,d][1,2]diselenole (dt-Se2naph). Bromination of mt-Se2naph results in dibromination of the naphthalene ring, rather than reaction at selenium, to give 4,7-dibromo-2-tert-butylnaphtho[1,8-c,d][1,2]diselenole (mt-Se2naphBr2). Reduction of the Se–Se bond in Se2naph, mt-Se2naph, dibenzo[c,e][1,2]diselenine (dibenzSe2), or diphenyl diselenide (Se2Ph2) with LiBEt3 H, followed by in-situ addition of [PtCl2{P(OPh)3}2] yields the four-coordinate mono- and dinuclear platinum(II) bis(phosphite) complexes [Pt(Se2naph){P(OPh)3}2] ( 1 ), [Pt(mt-Se2naph){P(OPh)3}2] ( 2 ), [Pt2(dibenzSe2)2{P(OPh)3}2] ( 3 ), cis-[Pt(SePh)2{P(OPh)3}2] ( 4 ), and trans-[Pt2(SePh)4{P(OPh)3}2] ( 5 ).PostprintPeer reviewe