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REASERCH PROJECTS for YOUNG RESEARCH TEAMS

REASERCH PROJECTS for YOUNG RESEARCH TEAMS. Molecular and Supramolecular Heterotrimetallic Systems: towards a new generation of molecular magnetic materials PN-II-RU-TE-2011-3-0126. Project Leader: Dr. Diana VISINESCU. 5.10.2011-5.10.2014. ABSTRACT.

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REASERCH PROJECTS for YOUNG RESEARCH TEAMS

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  1. REASERCH PROJECTS for YOUNG RESEARCH TEAMS Molecular and Supramolecular Heterotrimetallic Systems: towards a new generation of molecular magnetic materials PN-II-RU-TE-2011-3-0126 Project Leader: Dr. Diana VISINESCU 5.10.2011-5.10.2014

  2. ABSTRACT The present project focuses on designing heterotrimetallic magnetic materials with enhanced characteristics. A special emphasis is devoted to initiating, developing and/or combining new physical properties within the heterometallic systems enclosing cores of three different spin-carriers. The rational inclusion of 3d and/or 4f cations within the same molecular entity could generate new categories of heterotrimetallic complexes: photomagnets, luminescent or chiral compounds or with combined properties, namely magneto-luminescence or magneto-chirality. These new molecular materials open large perspectives in the developing of molecular “prototypes” for revolutionary optical, high-storage devices or in quantum computing. An important part of the project is related with the human resources, both senior researchers and young graduated or Ph.D. students being employed in this project. The research theme is very actual and reliable and the obtained results will be reported in national and international ISI rated publications.

  3. Objectives The main objective is the obtaining of polynuclear structures incorporating three different metal ions with enhanced magneto-optical properties (Scheme 1). Specific objectives: • Design and synthesis of heterotrimetallic nanomagnets Scheme 1 • Construction of 2D and 3D heterotrimetallic coordination polymers in order to generate classical molecule-based magnets with high critical temperatures. • Synthesis of novel (multi)functional heterotrimetallic molecular materials: photomagnetic complexes, photo-switchable nanomagnets or with combined properties, namely magneto-luminiscent or magneto-chiral systems.

  4. RESEARCH TEAM Project leader: Dr. Diana-Beatrice VISINESCU, Senior Researcher III Institute of Physical Chemistry “IlieMurgulescu”, Romanian Academy Research team members: 1. Dr. Maria-Gabriela ALEXANDRU post-doc researcher, University of Bucharest* 2. Dr. Traian-Dinu PASATOIU 2011-2012 – Ph.D. student, University of Bucharest* 2013- Senior Researcher III, University of Bucharest 3. Dr. Gabriela MARINESCU Senior Researcher III, Institute of Physical Chemistry “IlieMurgulescu” Romanian Academy 4. Dr. AugustinMadalin MADALAN Senior Researcher (lecturer), University of Bucharest 5. Dr. BogdanCiprian JURCA Senior Researcher (lecturer), University of Bucharest 6. AlinaSimona DINCA – Ph. D. student, University of Bucharest* New research team members (from 1.06.2013): Andrei Alunel PATRASCU – M. Sci. student, University of Bucharest* Maria COCIS - technician, Institute of Physical Chemistry “IlieMurgulescu”, Romanian Academy *The post-doc researcher, Ph.D. and Master student follow(-ed) post-doc/Ph.D./Master programs of the University of Bucharest. His/her experience in the synthesis, crystallization and characterization of the heterobi- and trimetallic complexes is very important in accomplishing the objectives of the research project.

  5. National and International Collaborations University of Bucharest, Faculty of Chemistry Acad. Marius ANDRUH Institute of Macromolecular Chemistry “Petru Poni”, Iasi Academia Romana Dr. Sergiu SHOVA Instituto de Ciencia Molecular (ICMol) Universitat de València SPANIA Prof. Miguel JULVE Laboratoire de Chimie de Coordination, CNRS, Université de Toulouse, FRANTA Dr. Jean-Pascal SUTTER Institut de Chimie de la Matiere Condensee (ICMCB)/Centre de Recherche Paul Pascal -CNRS, Université de Bordeaux, FRANTA Dr. Rodolphe Clérac Dr. Corinne Mathonière

  6. MAIN RESEARCH FACILITIES Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy FTIR SPECTROMETER JASCO -4100 400-4000 cm-1 UV-Vis SPECTROMETER PERKIN-ELMER LAMBDA L35, 200-1100 nm JASCO FP-8300 SPECTROFLUORIMETER 200-650 nm INCUBATOR Memmert UNB500

  7. MAIN RESEARCH FACILITIES University of Bucharest, Faculty of Chemistry X-ray diffractometer on single-crystals Cryogenic SQUID magnetometer STOE IPDS II

  8. Internal and abroad short research stages Diana Visinescu 14-30 june 2012: a short research stage at Laboratoire de Chimie de Coordination (LCC) CNRS, Université Paul Sabatier, Toulouse, France – Dr. Jean-Pascal Sutter AC and DC magnetic measurements for heterotrimetallic compounds Project for one publication, preparing of manuscript Diana Visinescu, Maria-Gabriela Alexandru and Alina Simona Dinca 25-27 july 2012: aresearch visit at Institute of Macromolecular Chemistry “Petru Poni”, Romanian Academy, Iasi – Dr. Sergiu Shova Special X-ray diffraction measurements on single-crystals Diana Visinescu 3-30 september and 12-30 november 2012: shortresearch stages at Instituto de Ciencia Molecular (ICMol), Universitat de Valencia– Prof. Miguel Julve Synthesis of new heteroleptic 3(4,5)d cyano-based metalloligands. Testing the reactivity of the new obtained metallocyanates against cationic complexes. Synthesis of new heterotrimetallic complexes by using the new metallocyanate ligands. Structural and DC/AC magnetic measurements of the obtained precursors and compounds. Preparing of manuscripts.

  9. 2011-2012 RESULTS National and International Conferences Vth International Conference on Molecular Materials. MOLMAT 2012 – Barcelona, 3-6 july 2012 Contributions- 2 posters 1. Two structural types in one synthesis: the simultaneous formation of trinuclear and one-dimensional structures of 3d-4f-5d heterotrimetallic complexes, autori: Diana Visinescu, Maria-Gabriela Alexandru, Bogdan Jurca, Augustin M. Madalan, Rodolphe Cérac and Marius Andruh 2. First heterotrimetallic complexes using a 5d heteroleptic cyanido-metalloligand, autori: Maria-Gabriela Alexandru, Diana Visinescu, Augustin M. Madalan, Francisc Lloret, Miguel Julve and Marius Andruh 40th International Conference on Coordination Chemistry, Valencia- 9-13 september, 2012 Contributions- 4 posters 1. New families of heterotrimetallic nanomagnets, autori: Diana Visinescu, Maria-Gabriela Alexandru, Augustin M. Madalan, Marius Andruh, Jean-Pascal Sutter, Rodolphe Clérac and Ie-Rang Jeon 2. New 0-D heterotrimetallic CuII-Mo(W)V-LnIII complexes. Structural and magnetic properties. Autori: Maria-Gabriela Alexandru, Diana Visinescu, Augustin M. Madalan, Rodolphe Clérac, Corine Mathonière, Marius Andruh 3. Heterodimetallic ZnII-LnIII complexes with tunable luminescent properties, Autori: Traian D. Pasatoiu, Augustin M. Madalan, Carmen Tiseanu and Marius Andruh. 4. Dodecanuclear [Cu6IILn6III] nanoclusters (Ln = Gd, Tb, Dy, Ho). A new magnetic refrigerant. Alina S. Dinca, Alberto Ghirri, Augustin M. Madalan, Marco Affronte, Francesc Lloret, Miguel Julve and Marius Andruh XXXIInd National Chemistry Conference, Caciulata, 3-5 october 2012 Contribution – one oral presentation Traian D. Pasatoiu, Augustin M. Madalan,Marius Andruh : Self-assembled octameric water clusters and infinite water tapes found in 3d-4f complexes with hexadentate Schiff-base ligands

  10. 2011-2012 RESULTS PUBLICATIONS 2 Published articles • [W(bipy)(CN)6]−: A Suitable Metalloligand in the Design of Heterotrimetallic Complexes. The First CuIILnIIIWV Trinuclear Complexes, M.-G. Alexandru, D. Visinescu, A. M. Madalan,F. Lloret, M. Julve, M. Andruh, Inorg. Chem.,2012, 51, 4906. 2. Self-assembly of [CuIITbIII]3+ and [W(CN)8]3− tectons: a case study of a mixture containing two complexes showing slow-relaxation of the magnetization, D. Visinescu, I.-R. Jeon, A. M. Madalan, M.-G. Alexandru, B. Jurca, C. Mathonière, R. Clérac, M. Andruh, Dalton T., 2012, 41, 13578. 1 submitted article Low-Dimensional 3d-4f Complexes Assembled from Low-Spin [FeIII(phen)(CN)4]- Anions, D. Visinescu, L. M. Toma, O. Fabelo, C. Ruiz-Pérez, F. Lloret, M. Julve

  11. Details regarding the main results in the period 2011-2012 Dalton Trans., 2012, 41, 13578-13581 The synthesis and magneto-structural characterization of new heterotrimetallic systems {(CuIIvalen*)TbIIIWV} exhibiting nanomagnetic properties. MT vs.T plot at 1000 Oe for a polycrystalline sample of 1 and 2. Inset: Mvs. H/T plot between 1.8 and 8 K. 1 - By reacting the heterobimetallic complex {(CuIIvalen)TbIII} with (NHBu3)3[WV(CN)8] two heterotrimetallic complexes have been obtained: [{W(CN)8}Cu(valen)Tb(OH2)5]·2H2O (1) and [{W(CN)8}Cu(valen)Tb(OH2)4]·CH3CN·H2O (2) . - Compound 1 has a discrete trinuclear structure, while compound 2 is a monodimensional coordination polymer with a zig-zag motif. 2 -The trinuclear complex {CuIITbIIIWV} (1) shows a single-molecular magnet (SMM) behaviour and compound 2 exhibits a single-chain magnet (SCM) properties with a relaxation time  = 110-9 s. The anisotropic energy barrier is Ueff = 53.9K representing the highest value for {CuIITbIII}-based systems reported to date. (a) ’ vs. T, (b) ” vs. T, (c) ’ vs.  and (d) ” vs.  data measured on a polycrystalline sample of 1 and 2 without dc field at different temperatures and ac frequencies. Inset: τvs. T-1 plot. Solid line is the best fit to the Arrhenius law. Molecular structure of 1 (up) and a fragment of the zig-zag chain of 2 (bottom). * valen represent a side-off Schiff-base compartmental ligand resulted from a 2:1 condensation reaction between o-vanillin and ethylenediamine

  12. Details regarding the main results in the period 2011-2012 Inorg. Chem., 2012, 51, 4906-4908 [WV(bpy)(CN)6]- - A new metalloligand to assemble heterotrimetallic systems (bpy = 2,2’-bipyridine) -A new family of heterotrimetallic complexes was obtained by reacting [Cu(valpn*)] precursor with trivalent lanthanide ions [Ln(III)= Gd, Dy, Tb] and with [WV(bpy)(CN)6]- anions. -The three compounds are isostructural, their structure being trinuclear and made-up from [WV(bpy)(CN)6]- coordinated through a single-cyanide group to the heterobimetallic unit {CuII(valpn)LnIII} (Ln = Gd, Tb, Ho) . The molecular structure of [(CN)5(bipy)WV(CN)CuII(valpn)Gd(O2NO)2(H2O)] -For Gd(III) derivative, the Tvs. T plot indicate a predominant ferromagnetic interaction, the values of the coupling constant J, theLandé factor and zero-field splitting being estimated with the spin hamiltonian: JCu(II)-Gd(III) = + 8.90 cm-1, jCu(II)-W(V) = -0.83 cm-1 si D = 1.85 cm-1. -The value of the magnetic interaction between copper(II) and gadolinium(III) was correlated with the value of the dihedral angle between <OCuO> and <OGdO> linked by phenoxo- bridge. The smaller is the dihedral angle (in this case 12o) , the higher is the J value. Though the Dy and Tb derivatives did not show AC signals, these compounds represent the first examples of heterotrimetallic systems obtained by employing a 5d heteroleptic metalloligand. T vs. T plot for [(CN)5(bipy)WV(CN)CuII(valpn)Ln(O2NO)2(H2O)]: experimenatal(); besti-fit results (---); Inset: M vs. Hplot recorded at 2K. *valpn is a side-off compartmental ligand resulted from the 2:1 condensation reaction of o-vanillin and propylene diamine

  13. BUDGET 2011-2012

  14. Training school 2013 Diana Visinescu andMaria-Gabriela Alexandru 9-22 june 2013 – participation to The Zürich Crystallography School (5th edition), held in Institute of Organic Chemistry at the University of Zürich, Switzerland The aim of the school was to provide the essential theory and practice of small-molecule single-crystal X-ray crystallography. The course was also a hands-on approach to crystallography, offering the opportunity to measure and solve the structure of single-crystals brought by each participant, after learning the basics in crystallography. The practical/theoretical knowledge offered by the intensive crystallography school is extremely important in order to perform X-ray diffraction measurements on single-crystals and to analyze the dataset for a complete structural characterization of complexes and also for a better understanding of their magnetic behaviour. Research stage Diana Visinescu andMaria-Gabriela Alexandru 22june-4 august 2013 – research stage at ICMol, Universitat de Valencia-Prof. Miguel Julve Synthesis of new heteroleptic 4(5)d cyano-based metalloligands. Testing the reactivity of the new obtained metallocyanates against cationic complexes. Structural and DC/AC magnetic measurements of the obtained precursors and compounds. Preparing of manuscripts.

  15. RESULTS 2013 Conferences 18th Romanian International Conference on Chemistry and Chemical Engineering, RICCCE XVIII, 4-7 september 2013, Sinaia Contributions- 2 oral presentations Towards heterotrimetallic nanomagnets, D. Visinescu, M.-G. Alexandru, A. Madalan and M. Andruh, oral communication New polymetallic systems obtained using anions of organic acids as spacers, Traian D. Pasatoiu, Augustin M. Madalan, Marius Andruh, oral communication International Conference of Physical Chemistry-ROMPHYSCHEM 15, 11-13 september 2013, Bucharest Contribution - one oral presentation New molecular-based magnetic materials. D. Visinescu, M.-G. Alexandru, A. Madalan, B. Jurca, M. Andruh, J.P. Sutter and R. Clérac, oral communication

  16. RESULTS 2013 Publications Two published article 1. Low-Dimensional 3d–4f Complexes Assembled by Low-Spin [FeIII(phen)(CN)4]− Anions, Diana Visinescu, Luminita Marilena Toma, Oscar Fabelo, Catalina Ruiz-Pérez, Francesc Lloret, and Miguel Julve, Inorg. Chem. 2013, 52, 1525-1537. 2. Synthesis, crystal structure and magnetic properties of a new cyanide-bridged mixed-valence copper(I)/copper(II) clathrate, Diana Visinescu, Oscar Fabelo, Catalina Ruiz-Pérez, Francesc Lloret, and Miguel Julve, Inorg. Chem. Commun., 2013, 35, 252-254. One manuscripts in progress Magneto-structural diversity of 3d-4f-4(5)d Heterotrimetallic complexes, D. Visinescu, M.-G. Alexandru, A. M. Madalan, M. Andruh, C. Duhayon, J.-P. Sutter

  17. Details regarding the main results in 2013 Inorg. Chem., 2013, 52, 1525-1537 Type 1 Type 2 The reactivity of [FeIII(phen)(CN)4]- anion against lanthanide(III) ions has been tested in order to use the tetracyano- heteroleptic unit to assemble 3d-4f-3d’ heterotrimetallic complexes (phen = 1,10-phenantroline). Low-symmetrical [FeIII(phen)(CN)4]- unit (C2v), with a significant orbital contribution of the iron(III), has a great potential to act as metalloligand in the assembly of heterotrimetallic systems with SMM/SCM properties. Surprisingly, the examples of 3d-4f complexes obtained using as precursor the six-coordinated [FeIII(phen)(CN)4]- anion are scarce. The reaction of (PPh4)[FeIII(phen)(CN)4]with Ln(NO3)3 and bpym (as auxiliary ligand) afforded a series of 3d-4f isomorphous compounds, with structure of double-chain (assembled from cyanide-bridged {Fe2IIILnIII} heterotrimetallic units) and a “ladder-like” topology (Ln = Gd, Tb, Sm, structural type 1) and, in one case (Ln = Pr) the formation of an extended {FeIIIPrIII} bi-dimensional network (structural type 2). For Gd derivative, the analysis of the magnetic data revealed weak antiferromagnetic (AF) interactions between Fe(III) and Gd(III) ions via cyanide-bridges (J = -0.49 cm-1)and very weak AF interactions between gadolinium(III) ions across bpym bridges (J = -0.039 cm-1) . For {Fe2IIISm} is observed a predominant ferromagnetic interaction, while in the case of {Fe2IIITb} chains and {FeIIIPrIII} layers the magnetic coupling is very weak AF. MT vs. T plot for structural type 1 (Ln = Gd). Inset: magnetization vs H plot for Gd derivative at 2.0 K.

  18. Details regarding the main results in 2013 [CuI(CN)3/2]1/2- Inorg. Chem. Comm., 2013, 35, 252-254 • A new 5d cyano-based metalloligand, [WIV(CN)4O2]4- in order to design photomagnetic heterotrimetallic molecular materials. [{CuII(tren)}2(-CN)]3+ Homo- and heteroleptic polycyanate MoIV/WIV-containing metaloligands are commonly employed in the assembly of heterometallic CuII-MoIV/WIV complexes that exhibit photomagnetic properties. A new 5d tetracyano-tungstate(IV) precursor, with the formula [WIV(CN)4O2]4-, has been synthesized and tested in reaction with copper(II) cationic complexes. The in situ hydrolisis of the tetracyanometallate complex led to unexpected results. The released cyanide groups has reacted with copper(II) ions and tren [tren = tris(2-aminoethyle)amine] ligand to finally afford a unique cyano-based clathrate, namely [CuI2(CN)3][{CuII(tren)}2(-CN)](CF3SO3)2. The structure of the obtained compound consists in cationic single-cyanide copper(II) dimers, [{CuII(tren)}2(-CN)]3+, stacked between two-dimensional cyanide-based copper(I) networks. The analysis of the magnetic properties showed a very strong AF coupling between the two copper(II) cations across single-cyanide bridge from the binuclear units (J = -160 cm-1). Perspective view of the ionic inclusion compound MT (o) and M (∆) against T plots for the cyanide-based clathrate. The solid line is the best-fit curve.

  19. in progress 2013 RESULTS Magneto-structural diversity of 3d-4f-4(5)d heterotrimetallic systems tuned by the structural modifications of the compartmental ligand The structural topology of the heterotrimetallic complexes and their magnetic behaviour are strongly influenced by subtle structural modifications operated on the Schiff-base compartmental ligand and also by the coordination mode of the metalloligand, namely the octacyanometallates(V) anions. Thus, by using valpn ligand associated with a tris-coordinated mode of [M(CN)8]3- (M = Mo, W) anions trinuclear phenoxo-bridged {CuII2LnIII} heterobimetallic nodes are stabilized and afford heterotrimetallic {CuII2LnIIIMV} chains (type 1). A more rigid compartment of the side-off ligand (valdp*) and a bis-monodentate coordination mode of the octacyanometallate anions modify the chain topology assembled from binuclear {CuIILnIII} heterobimetallic units in a zig-zag fashion (type 2). A third structural type is obtained in the case of valdp ligand, when bulky lantanide(III) cations are employed (Ln = La, Pr) (type 3). The Tb derivatives of type 1 complex series showed a SCM behaviour. {CuIITbIIIMoV} {CuIITbIIIWV} Field-induced slow relaxation of magnetization (HDC = 3000 Oe) Type 1 Type 2 Type 3 *valdp is a side-off compartmental ligand resulted from the 2:1 condensation reaction of o-vanillin and 1,2-diamino propane

  20. BUDGET 2013 (in progress)

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