M. Lagrenee

Bio: M. Lagrenee is an academic researcher from Lille University of Science and Technology. The author has contributed to research in topics: Crystal structure & Derivative (chemistry). The author has an hindex of 4, co-authored 10 publications receiving 40 citations. Previous affiliations of M. Lagrenee include university of lille.

Structure of mononuclear bis{aqua[2,2'‐(1,3,4‐oxadiazole‐2,5‐diyl)dipyridine‐N,N']}copper(II) diperchlorate

Abstract: [Cu(C 12 H 8 N 4 O) 2 (H 2 O) 2 ] (ClO 4 ) 2 cristallise dans P2 1 /n avec a=13,579, b=10,904, c=10,329 A, β=103,5 o , z=2; affinement jusqu'a R=0,053. La structure consiste en couches alternees de cations centrosymetriques mononucleaires et d'anions ClO 4 − ; couches probablement liees par des liaisons hydrogene. Chaque coordinat est bidente et relie a l'atome de cuivre par l'atome d'azote de l'oxadiazole et l'atome d'azote de l'une des pyridines. Les deux molecules d'eau completent la bipyramide a base carree entourant l'ion metallique

Structure et interactions magnétiques de composés polymétalliques de basse dimensionnalité

Abstract: Le 2,5 - Bis (pyridin - 2 yl) - 1, 3, 4 - oxadiazole (b.p.o.) est un ligand capable de coordiner un ou plusieurs atomes de Cu(II) selon les conditions experimentales. La complexation par CuCl 2 conduit a la cristallisation d’especes mononucleaires meme en presence d’un large exces de Cu (II). L’introduction dans le milieu reactionnel d’un chlorure de metal bivalent, tel que Ni, Co, Mn, entraine la formation d’un complexe cuivrique polymetallique cristallisant en chaine unidimensionnelle. Les structures cristallines ont ete resolues par diffraction des rayons X. Le comportement paramagnetique de la chaine montre qu’il n’y a pas de couplage entre les atomes de Cu(II)

Hydrolyse lente du cycle oxadiazole: structure d'un complexe binucléaire du CuII avec le pyridoyl-2' pyridinecarbohydrazide

Abstract: [Cu 2 (C 12 H 8 N 4 O 2 ) (H 2 O) 3 ] (NO 3 ) 2 •2H 2 O cristallise dans P2 1 /c avec a=7,977, b=15,044, c=16,629 A, β=97,98°, Z=4; affinement jusqu'a R=0,042. La structure caracterise un complexe binucleaire du coordinat (2'-pyridoyl) pyridinecarbohydrazide obtenu par ouverture du cycle oxadiazole en 2,5-bis(2-pyridyl) 1,3,4-oxadiazole

The Halogen Bond

Abstract: The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

A Reversible Structural Interconversion Involving [M(H2pdc)2(H2O)2]⋅2 H2O (M=Mn, Fe, Co, Ni, Zn, H3pdc=3,5‐pyrazoledicarboxylic acid) and the Role of A Reactive Intermediate [Co(H2pdc)2]

Abstract: A new type of hydrogen bonded networks [M(H2pdc)2(H2O)2]⋅2 H2O [M=Mn (1), Fe (2), Co (3), Ni (4), Zn (5); H3pdc=3,5-pyrazoledicarboxylic acid] have been synthesized via hydrothermal reactions and their structures have been characterized. Upon a cooling-heating cycle, these compounds undergo a reversible structural interconversion process via hydration-dehydration: [M(H2pdc)2(H2O)2]⋅2 H2O[M(H2pdc)2]. The process is associated with distinct color changes. The dehydrated [M(H2pdc)2] (M=Mn, Fe, Co, Ni, and Zn) are amorphous and highly reactive. Further chemical reactions of these reactive intermediates show that they may act as effective precursors towards assembly of new supramolecular compounds that may otherwise be inaccessible by other synthetic routes. An interesting structure containing an “open-box” molecule [Co4(Hpdc)4(py)12]⋅4 py⋅2 H2O⋅2 CH3OH (6) (py=pyridine) has been isolated by using dehydrated [Co(H2pdc)2] as the precursor, and its crystal structure has been analyzed. Crystal data for 1–6: monoclinic, space group P21/c and Z=2 with a=10.186(2), b=12.473(2), c=6.831(1) A, β=108.80(3)° (1); a=9.896(2), b=12.402(2), c=6.810(1) A, β=108.15(3)° (2); a=9.981(2), b=12.426(2), c=6.807(1) A, β=108.23(3)° (3); a=9.896(2), b=12.402(2), c=6.810(1) A, β=108.15(3)° (4); a=10.001(2), b=12.430(2), c=6.834(1) A, β=108.32(3)° (5); a=9.9617(1), b=18.5080(2), c=28.4786(3) A, β=93.076(1)° (6).

Metal-induced reductive ring opening of 1,2,4,5-tetrazines: three resulting coordination alternatives, including the new non-innocent 1,2-diiminohydrazido(2-) bridging ligand system.

Abstract: Reaction of 3,6-diaryl-1,2,4,5-tetrazines (aryl = R = phenyl, 2-furyl or 2-thienyl) with 2 equiv of Ru(acac)2(CH3CN)2 results in reductive tetrazine ring opening to yield diruthenium complexes [(acac)2RuIII(dih-R2-)RuIII(acac)2] bridged by the new 1,2-diiminohydrazido(2−) (dih-R2- = HNC(R)NNC(R)NH2-) ligands. rac/meso diastereoisomers could be detected and separated for the compounds with R = phenyl and 2-thienyl, all species are diamagnetic and were characterized by 1H NMR spectroscopy. Crystal structure determination of the meso isomers with R = phenyl and 2−thienyl confirmed the 1,2-diiminohydrazido formulation through long N−N (≈1.40 A) and short CN(H) bonds (≈1.31 A), implying two bridged ruthenium(III) centers at about 4.765 A distance with strong antiferromagnetic coupling. The complexes undergo two reversible and well-separated one-electron reduction and oxidation processes, respectively. EPR Spectroscopy of the paramagnetic intermediates with comproportionation constants Kc > 1012 and UV−vis−NIR ...