Résumés Année 2016

"Influence of the supramolecular order on the electrical properties of 1D coordination polymers based materials"

C. Musumeci, S. Osella, L. Ferlauto, D. NiedzialekI, L. Grisanti, S. Bonacchi, A. Jouaiti, S. Milita, A. Cieslieski, D. Beldonne, M. W. Hosseini, P. Samori, Nanoscale, 2016, 8, 2386-2394.(download.pdf)

Abstract: The generation, under self-assembly conditions, of coordination polymers on surface based combinations of a terpyridine-antracene-pyridine based tecton and Co(II) or Pd(II) cations is primarily governed by the coordination geometry of the metal center (octahedral and square planar respectively). While the octahedral Co(II) based polymer self-assembles in insulating films exhibiting randomly oriented crystalline domains, the planarity of Pd(II) based polymers leads to the formation of conductive π-π stacked fibrillar structures exhibiting anisotropically oriented domains. In the latter case, the favorable Pd-Pd and anthracene-anthracene wavefunction overlaps along the fiber direction are responsible for the large electronic couplings between adjacent chains, whereas small electronic couplings are instead found along individual polymer chains. These results provide important guidelines for the design of conductive metal coordination polymers, highlighting the fundamental role of both intra- as well as inter-chain interactions, thus opening up new perspectives towards their application in functional devices.)

"Molecular tectonics: 1D tubular type and 3D diamond like mercury (II) coordination polymers based on pyridyl appended p-tert-butyl-tetrathiacalix[4]arene"

A. Ovsyannikov, S. Ferlay, S. E. Solovieva, I. S. Antipin, A. I. Konovalov, N. Kyritsakas, M. W. Hosseini, Macroheterocycles, 2016, 9, 17-22.(download.pdf)

Abstract: 1D tubular-type and 3D diamond-like coordination polymers are formed upon combining pyridyl appended p-tert-butyl-tetrathiacalix[4]arene in 1,3-alternate conformation  tectons 4 and 5 with mercury (II) chloride.

"Molecular tectonics: dimensionality and geometry control of silver coordination networks based on pyrazolyl appended thiacalixarenes"

A. Ovsyannikov, S. Ferlay, M. H. Noamane, R. Abidi, S. E. Solovieva, I. S. Antipin, A. I. Konovalov, N. Kyritsakas, M. W. Hosseini, CrystEngComm, 2016, 18, 691-703.(download.pdf)

Abstract: Combinations of six new coordinating tectons (3-8) tetrakis-pyrazolyl appended calix[4]arenes, blocked in 1,3-A conformation, based on 1 (tetrathiacalix[4]arene) and 2 (tetrathiatetramercaptocalix[4]arene) derivatives, with AgX salts (X = NO₃^-, BF₄^-, XF₆^- (X = P, As and Sb)) lead to nine new silver coordination networks. The flexible nature of tectons 3-8 (length of the spacer between the macrocycle and the pyrazolyl coordinating unit), their high number of potential coordinating sites and the loose coordination demand of Ag⁺ cation lead to the formation of a large variety of networks with different dimensionality: from 1D (5-AgSbF₆, 5-AgBF₄, 7-AgSbF₆ and 8-AgNO₃) to extended 2D (6-AgBF₄ and 8-AgSbF₆) and to a series of three isostructural porous diamond-like 3D architectures (6-AgXF₆ (X = P, As and Sb)).

"Amidinium-templated 2D [MnCr] Bimetallic Oxalate-Based Networks: The Influence on Structure and Magnetism Explored by Combining Experience and Theory"

M. CATALIN, S. SAUREU,C. DE GRAAF, S. FERLAY, M. W. HOSSEINI, V. ROBERT, C. TRAIN, EURJIC, 2016, 4185–4193.

Abstract: Three X²⁺ bisamidinium dications are used as template for the formation of oxalate-based bimetallic [MnCr] compounds 1-3 of formula X[Mn^II(CH₃OH)Cr^III(ox)₃]₂·nS (X²⁺ = C₁₄N₄H₂₀²⁺ (cation A, compound 1), C₁₄O₂N₄H₂₀²⁺ (cation B, compound 2), C₁₆N₄H₂₄²⁺ (cation C, compound 3); n=4 (1-2), 2 (3); S= CH₃OH (1-2), CH₃CN (3)). The single-crystal X-rays analysis reveals that in 1-3, a Mn-Cr oxalate-bridged bimetallic coordination network is formed, displaying corrugated two-dimensional (2D) layers based on heptacoordinated manganese(II) ions, with six oxygen atoms from three bis(bidentate) oxalate ions and one oxygen atom from a coordinated methanol molecule in the coordination sphere, one of the three oxalate linkages being slightly to heavily disymmetrical. In all cases, according to Continuous Shape Measurements (CSM), Capped Trigonal PRism (CTPR) is the ideal polyhedron that is the closest from the  coordination environment of manganese(II) observed in 1-3. Measurements of the magnetic properties revealed a continuous increase of the _MT product, _M being the magnetic susceptibility, when the temperature is lowered from 300K to 5K, indicating the presence of a dominant ferromagnetic interaction in 1-3. The Curie-Weiss temperatures deduced from the fit of the magnetic sus.eptibility in the paramagnetic phase are 5.87K, 4.40K and 3.98K for 1, 2 and 3 respectively and from a mean field approach, an average weak ferromagnetic exchange interaction of 0.62K, 0.42K and 0.54K for 1, 2 and 3 respectively, can be deduced. Ab initio calculations up to the DDCI-2 level were performed on [MnCr] dimeric units. They allow to evaluate the exchange interaction for each type of bridges present in the three compounds. An effect of the asymmetry of the bridge on the exchange interaction is observed but not in a systematic way.

"Molecular tectonics: homochiral coordination networks based on pyridyl-substituted cyclic tetrapeptides"

A. GANTZ, C. XU, A. GUENET, H. KELM, N. KYRITSAKA, J.-M. PLANEIX,S. KUBIK, M. W. HOSSEINI, CrystEngComm, 2016, 18, 7685 - 7689.

Abstract: Upon combining enantiopure bis-4-pyridylphenyl-substituted tetracyclopeptides with HgCl₂ and CdCl₂, homochiral 1D zig-zag coordination networks were obtained while the use of bis-4-pyridyl-substituted tetracyclopeptide with HgCl₂ led to the formation of a different 1D coordination network.

"Perspectives in Molecular Tectonics"

M. W. HOSSEINI, Macrocyclic and Supramolecular Chemistry, Ed. R. M. Izatt, Wiley 2016, pp 73-91.

Abstract: The design and construction of periodic architectures in the crystalline phase are attracting considerable interest over the last two decades. For both design and analysis of molecular crystals, a strategy called molecular tectonics which is based on the formation of molecular networks through the design of complementary tectons or molecular construction units has been developed. The generation of molecular networks and subsequently of crystals is achieved by self-assembly processes based on repetitive molecular recognition events. This approach, combining supramolecular synthesis and self-assembly processes in the solid state, is operational and versatile and allows the design and construction of a variety of complex purely organic or hybrid architectures. Molecular tectonics concepts, definitions and scope will be presented and illustrated by a variety of tectons and networks.

"Phosphorus(V) Porphyrin Based Molecular Turnstiles"

I. N. MESHKOV, V. BULACH, Y. G. GORBUNOVA, N. KYRITSAKAS-GRUBER, M. S. GRIGORIEV, A. Y. TSIVADZE, M. W. HOSSEINI, Inorg. Chem, 2016, 55, 10774 –10782.

Abstract: A new cationic molecular turnstile based on P(V) porphyrin backbone bearing two pyridyl interaction sites, one at the meso-position of the porphyrin and the other on the handle connected to the porphyrin through P-O bonds, was designed and synthesized. The dynamic behavior of the turnstile 2, investigated by 1D and 2D ¹H-NMR techniques, showed that in the absence of an effector, the turnstile is in its open state and undergoes a free rotation of the rotor (the handle) around the stator (the porphyrin backbone). In the presence of an external effector such as Ag⁺ cation or H⁺, the turnstile is switched to its closed states 2-Ag⁺ and 2-H⁺ respectively. The locking/unlocking process is reversible and may be achieved by precipitation of AgBr upon addition of Et₄NBr in the case of the silver locked turnstile or by addition of Et₃N in the case of the proton locked turnstile.

"Molecular tectonics: tetracarboxythiacalix[4]arene derivatives as tectons for the formation of hydrogen-bonded networks"

A. S. OVSYANNIKOV, M. N. LANG, S. FERLAY, S. E. SOLOVIEVA, I. S. ANTIPIN, A. I. KONOVALOV, N. KYRITSAKAS, M. W. HOSSEINI, CrystEngComm., 2016, 18, 8622 - 8630.

Abstract: A series of thiacalix[4]arene derivatives blocked in 1,3-alternate conformation and bearing four carboxylic acids has been designed and synthesized. These compounds, owing to the H-bond donor (OH moiety) and acceptor (C=O group)  nature of the carboxylic acid moieties behave as self-complementary tectons and lead to the formation of tubular 1D H-bonded networks in the crystalline phase. Upon deprotonation of the self-complementary neutral compounds 4-8, i.e. transformation of the carboxylic moieties into carboxylates, anionic tectons are generated. Their propensity to form H-bonded networks in the presence of the dicationic H-bond donor tecton A²⁺, designed to behave as a molecular staple interconnecting two carboxylates moieties, 1- and 2-D H-bonded networks are formed under self-assembly conditions.

"Pre-organization of clefts for Ag-π interactions in Zn(II) bisdipyrrin helicates for the construction of heterometallic networks"

S. BAUDRON, M. W. HOSSEINI, Chem. Comm., 2016, 52, 13000 - 13003.

Abstract: Coordination of 2,2’-bisdipyrrin based ligands to Zn(II) cation leads to the formation of binuclear helicates with pre-organized pyrrolic strands as well as peripheral aromatic moieties for Ag-π interactions, thus affording crystalline heterometallic networks upon further interactions with Ag(I) salts without the assistance of additional heteroatom-based coordinating units.