The 1H-pyrazoles have high versatility and ability to form hydrogen-bonded supramolecular materials. In this study, the thermal stability, fluorescence, and H-bonding ability of the studied 3,5-dimethyl-4-(4-X-phenyl)-1H-pyrazoles showed large differences depending on the terminal substituent. Supramolecular structures were analyzed using X-ray diffraction and Hirshfeld surface calculations. Compounds were found to arrange in different hydrogen-bonded structures, depending on the substitution at the para position of the phenyl ring (X = OCH3, NO2, NH2). The methoxy-substituted compounds arranged in dimers through methanol bridges, the nitro-substituted compound formed supramolecular polymers or catemers, and the amino-substituted compound gave rise to a new structure based on a 2D hydrogen-bonded network.

The synthesis and electrochemical and optical characterizations of four new 4H-pyranylidene-based push-pull molecules are reported herein as well as their evaluation as donor materials for organic photovoltaics. Studied systems exhibit good absorption properties and appropriate LUMO levels for a photoinduced electron transfer to C60. Bilayer organic solar cells fabricated from these new donors and C60 as the acceptor gave photocurrent however with low power conversion efficiencies. As shown by X-ray diffraction and theoretical calculations, titled molecules present a twisted structure which may prevent the formation of suitable π-π contacts between adjacent molecules hence explaining their low photovoltaic performance.

Phosphorescence in the liquid crystal state with one of the highest quantum yield values, 42%, at room temperature is reported.

The ability of a star-shaped tris(triazolyl)triazine derivative to hierarchically build supramolecular chiral columnar organizations through the formation of H-bonded complexes with benzoic acids was studied from a theoretical and experimental point of view. The combined study has been done at three different levels including the study of the structure of the triazine core, the association with benzoic acids in stoichiometry 1:3, and the assembly of 1:3 complexes in helical aggregates. Although the star-shaped triazine core crystallizes in a non-C(3)conformation, theC(3)-symmetric conformation is theoretically predicted to be more stable and gives rise to a favorableC(3)supramolecular 1:3 complex upon the interaction with three benzoic acids in their voids. In addition, calculations at different levels (DFT, PM7, and MM3) for the 1:3 host-guest complex predict the formation of large stable columnar helical aggregates stabilized by the compact packing of the interstitial acids by pi-pi and CH...pi interactions. The acids restrict the movement of the the star-shaped triazine cores along the stacking axis causing a template effect in the self-assembly of the complex. Theoretical predictions correlate with experimental results, since the interaction with achiral or chiral 3,4,5-(4-alkoxybenzyloxy)benzoic acids gives rise to supramolecular complexes that organize in bulk hexagonal columnar mesophases stable at room temperature with intracolumnar order. The existence of supramolecular chirality in the mesophase was determined for complexes formed by acids derived from (S)-2-octanol. Chiral aggregation was also evidenced for complexes formed in dodecane.

The binuclear platinum(IV) complexes [NBu4](2)[Pt-2(IV)(mu-Cl)(2)(C6F5)(4)Cl-4] (2) and [Pt-2IV(mu-C8H6N4)(2)(C6F5)(4)Cl-4] (4) have been synthesized by oxidative addition of chlorine to the binuclear platinum(II) species, but [NBu4](2)[Pt-2IV(mu-OH)(2)(C6F5)(4)Cl-4] (3) has been synthesized by substitution of the chloride bridges of the platinum(IV) complex. The square planar platinum environments of the Pt(II) starting materials change, as expected, to Pt(IV) octahedral environments with the chloride ligands in trans-position. Only minor changes in the Pt-X (X = Cl-bridge, OH) interatomic distances are produced because of the oxidation. Depending on the size of the bridging ligands and also probably the anionic character of the diplatinum( IV) complexes, the apical chloride ligands can still act as bridges toward other Pt centers. Thus, the organometallic tetra-nuclear mixed-valence platinum(IV)-platinum(II) complexes with formulas [NBu4](2)[{Pt-IV(mu-X)(C6F5)(2)}(2)(mu-Cl)(4){Pt-II(C6F5)(2)}(2)] [X = Cl (5), OH (6)] were obtained by reaction of 2 and 3 with cis-[Pt-II(C6F5)(2)(thf)(2)]. The structures of complexes 2, 4 and 6 have been determined by single-crystal X-ray diffraction studies. These crystal structures confirm that the oxidative addition of the chlorine molecule to the platinum(II) complexes 2 and 3 takes place on the axial positions of the platinum centers suggesting a SN2 mechanism. On the other hand, the central core of the anion of 6 has a chair like conformation and the long PtPt distances (>3.2 angstrom) clearly exclude any Pt.center dot center dot center dot Pt interaction. On the other hand, cis-[(C6F5)(2)Pt(mu-C8H6N4)Pt(C6F5)(2)] (1) can be reduced either electrochemically or by reacting with [CoCp2] to the anion [Pt-2(mu-C8H6N4)(C6F5)(4)]-which in the last case, can be isolated as complex 7. According to the EPR studies the anion is not a mixed Pt(II)Pt(I) compound but a binuclear Pt(II) derivative with the anion [C8H6N4](-) as bridging ligand. (c) 2019 Elsevier B.V. All rights reserved.

We show that several qubits can be integrated in a single magnetic ion, using its internal electronic spin states with energies tuned by a suitably chosen molecular environment. This approach is illustrated with a nearly-isotropic Gd(III) ion entrapped in a polyoxometalate molecule. Experiments with microwave technologies, either three dimensional cavities or quantum superconducting circuits, show that this magnetic molecule possesses the number of spin states and the set of coherently addressable transitions connecting these states that are needed to perform a universal three-qubit processor or, equivalently, a d=8-level 'qudit'. Our findings open prospects for developing more sophisticated magnetic molecules which can result in more powerful and noise resilient quantum computation schemes.

A layered coordination polymer was synthesized from Zn(ii) and 6-(methylmercapto)purine (mMP-H) in N,N-dimethylformamide (DMF). Its structure and formula [Zn2(μ2-mMP)3(NO3)(DMF)(H2O)]n·nDMF were determined by single crystal X-ray diffraction.

Chromophores where a polyenic spacer separates a 4H-pyranylidene or benzothiazolylidene donor and three different butenolide nitriles have been synthesized and characterized. The role of 2(5H)-furanones as acceptor units on the polarization and the second-order nonlinear (NLO) properties has been studied. Thus, their incorporation gives rise to moderately polarized structures with NLO responses that compare favorably to those of related compounds featuring more efficient electron-withdrawing moieties. Derivatives of the proaromatic butenolide PhFu show the best nonlinearities. Benzothiazolylidene-containing chromophores present less alternated structures than their pyranylidene analogues, and, unlike most merocyanines, the degree of charge transfer does not decrease on lengthening the π-bridge.

The second-order NLO responses and spectroelectrochemical properties of donor–π–acceptor systems featuring a quinoid/aromatic thiophene unit have been studied.

A rapid thermal processing (RTP) technique combined with ozone/oxygen calcination was applied to activate and heal a 1.1 mm2section of a silicalite-1 giant monocrystal.

ChemInformVolume 45, Issue 3 Heterocyclic Compounds ChemInform Abstract: Push—Pull Systems Bearing a Quinoid/Aromatic Thieno[3,2-b]thiophene Moiety: Synthesis, Ground State Polarization and Second-Order Nonlinear Properties. A. Belen Marco, A. Belen Marco Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorRaquel Andreu, Raquel Andreu Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorSantiago Franco, Santiago Franco Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJavier Garin, Javier Garin Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJesus Orduna, Jesus Orduna Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorBelen Villacampa, Belen Villacampa Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorBeatriz E. Diosdado, Beatriz E. Diosdado Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJuan T. Lopez Navarrete, Juan T. Lopez Navarrete Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJuan Casado, Juan Casado Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this author A. Belen Marco, A. Belen Marco Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorRaquel Andreu, Raquel Andreu Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorSantiago Franco, Santiago Franco Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJavier Garin, Javier Garin Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJesus Orduna, Jesus Orduna Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorBelen Villacampa, Belen Villacampa Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorBeatriz E. Diosdado, Beatriz E. Diosdado Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJuan T. Lopez Navarrete, Juan T. Lopez Navarrete Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this authorJuan Casado, Juan Casado Dep. Quim. Org., Univ. Zaragoza-CSIC, E-50009 Zaragoza, SpainSearch for more papers by this author First published: 02 January 2014 https://doi.org/10.1002/chin.201403109Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References A. Belen Marco, Raquel Andreu, Santiago Franco, Javier Garin, Jesus Orduna, Belen Villacampa, Beatriz E. Diosdado, Juan T. Lopez Navarrete, Juan Casado, Push.lb.Pull Systems Bearing a Quinoid/Aromatic Thieno[3,2-b]thiophene Moiety: Synthesis, Ground State Polarization and Second-Order Nonlinear Properties., Org. Biomol. Chem., 2013, 11, 6338–6349. DOI: 10.1039/c3ob41278d; 10.1039/c3ob41278d CASPubMedWeb of Science®Google Scholar Volume45, Issue3January 21, 2014 ReferencesRelatedInformation

Supramolecular liquid crystals containing the unprecedented 4-aryl-1H-pyrazole unit are reported. This moiety is able to self-assemble by H-bonding to give columnar mesophases and also display luminescent properties in the visible region. The molecular structures consist of a polyalkoxybenzamide group substituted at the nitrogen atom by the 4-(3,5-dimethyl-1H-pyrazol-4-yl)phenyl unit. A family of compounds was synthesized to evaluate the supramolecular structures and the mesomorphic properties. The 3,4,5-tri-n-decyloxybenzamide derivative is a non-discoid molecule that displays a hexagonal columnar mesophase and a rectangular columnar mesophase. Powder X-ray diffraction studies show that these molecules are able to self-assemble in columns, and that a columnar stratum of the hexagonal columnar mesophase contains five molecules on average. A model for the columnar organization is proposed in which a self-assembled aggregate is formed by an antiparallel arrangement of the molecules partially interdigitated and interacts by hydrogen bonds. The amide group was changed by an ester group, in order to asses the role of the amide and pyrazole groups in the self-assembly. The ester compound also exhibited a columnar mesophase with similar cell parameters. This means that, together with the tapered shape of the molecule, the 1H-pyrazole moiety, and not the amide group, is essential for the aggregation leading to the mesomorphism. In addition, the single crystal structure of a model compound N-(4-(3,5-dimethyl-1H-pyrazol-4-yl)phenyl)benzamide was solved. The structure was a methanol solvate in which each pyrazole is engaged in hydrogen bonding to form a dimer through methanol bridges. The pyrazole molecules stack along the a axis and interact by hydrogen bonding through the amide groups to yield parallel infinite chains. Benzamide compounds are luminescent in the solid state and in the liquid crystalline state, in the blue region of the visible spectrum.

Chromophores bearing a 2-dicyanomethylenethieno[3,2-b]thiophene moiety in their quinoidal form have been synthesized, exploring for the first time the reactivity of this system towards aldehydes. Their ground state polarization and linear and second-order nonlinear optical (NLO) properties have been determined by a combined experimental and theoretical study, and compared to those of analogous compounds featuring an aromatic thienothiophene unit. Due to the gaining of aromaticity, quinoid systems have been found to display more polarized electronic ground states and higher NLO responses with respect to their aromatic counterparts.

The effect of time, composition and structure-directing agents on the synthesis of silicalite-1 and octadecasil zeolite millimeter-sized crystals has been studied. Crystals up to about 3 mm size range were obtained and special attention was paid to their aspect ratio, thermal behavior, monocrystallinity and textural properties by means of electronic and optical microscopy, powder and single-crystal X-ray diffraction (XRD), thermogravimetry and Ar adsorption. For the silicalite-1 crystals obtained after 34 days of hydrothermal synthesis, more than one thousand specimens from two repeated batches were measured along a, b and c axes. Reproducibility was thus assessed simultaneously with a statistical analysis to obtain cumulative and differential distributions of crystal dimensions. Single-crystal XRD evidenced a high degree of monocrystallinity, while thermal analyses suggested that crystals with sizes above 125 mu m have serious difficulties in activation, giving rise to high external specific surface area values upon Ar adsorption.

Two series of matched and mismatched donor–thiazole–acceptor chromophores have been synthesized to disclose the role that the orientation of the thiazole ring plays on their second-order nonlinear optical (NLO) properties. Whereas previous theoretical studies predict that the matched systems show markedly higher NLO responses, our experimental results do not parallel this trend, showing differences between regioisomers much lower than those predicted.

The formal [2 + 2] cycloaddition-cycloreversion (CA-CR) between 4-ethynyl-N,N-dimethylaniline and polyenic Donor-π-Acceptor (D-π-A) systems takes place to yield compounds bearing two donors and one acceptor. Structural, linear and second-order nonlinear optical (NLO) properties of the new molecules reveal the stronger polarization of these systems when compared to analogous merocyanines lacking the dimethylaminophenyl (DMA) ring.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.