scholarly journals Crystal structure of bromidopentakis(tetrahydrofuran-κO)magnesium bis[1,2-bis(diphenylphosphanyl)benzene-κ2 P,P′]cobaltate(−1) tetrahydrofuran disolvate

Author(s):  
Patience B. Girigiri ◽  
Stephanie H. Carpenter ◽  
William W. Brennessel ◽  
Michael L. Neidig

Structural characterization of the ionic title complex, [MgBr(THF)5][Co(dpbz)2]·2THF [THF is tetrahydrofuran, C4H8O; dpbz is 1,2-bis(diphenylphosphanyl)benzene, C30H24P2], revealed a well-separated cation and anion co-crystallized with two THF solvent molecules that interact with the cation via weak C—H...O contacts. The geometry about the cobalt center is pseudotetrahedral, as is expected for a d 10 metal center, only deviating from an ideal tetrahedral geometry because of the restrictive bite angles of the bidentate phosphane ligands. Three THF ligands of the cation and one co-crystallized THF solvent molecule are each disordered over two orientations. In the extended structure, the cations and THF solvent molecules are arranged in (100) sheets that alternate with layers of anions, the latter of which show various π-interactions, which may explain the particular packing arrangement.

2016 ◽  
Vol 72 (11) ◽  
pp. 1513-1516 ◽  
Author(s):  
Suk-Hee Moon ◽  
Donghyun Kang ◽  
Ki-Min Park

The asymmetric unit of the title compound, {[HgLCl2]·0.5CHCl3}n(L=N-(pyridin-4-ylmethyl)pyridin-3-amine, C11H11N3), contains one HgIIion, one bridgingLligand, two chloride ligands and a chloroform solvent molecule with half-occupancy that is disordered about a crystallographic twofold rotation axis. Each HgIIion is coordinated by two pyridine N atoms from two symmetry-relatedLligands and two chloride anions in a highly distorted tetrahedral geometry with bond angles falling in the range 99.05 (17)–142.96 (7)°. EachLligand bridges two HgIIions, forming polymeric zigzag chains propagating in [010]. In the crystal, the chains are linked by intermolecular N/C—H...Cl hydrogen bonds together with weak C—H...π interactions, resulting in the formation of a three-dimensional supramolecular network, which is further stabilized by C—Cl...π interactions between the solvent chloroform molecules and the pyridine rings ofL[chloride-to-centroid distances = 3.442 (11) and 3.626 (13) Å]. In addition, weak Cl...Cl contacts [3.320 (5) Å] between the chloroform solvent molecules and the coordinating chloride anions are also observed.


Author(s):  
Rayya A. Al Balushi ◽  
Muhammad S. Khan ◽  
Md. Serajul Haque Faizi ◽  
Ashanul Haque ◽  
Kieran Molloy ◽  
...  

In the crystal structure of the title compound, [Cu4Cl6O(C13H9N)4]·CH2Cl2, the core molecular structure consists of a Cu4 tetrahedron with a central interstitial O atom. Each edge of the Cu4 tetrahedron is bridged by a chlorido ligand. Each copper(II) cation is coordinated to the central O atom, two chlorido ligands and one N atom of the 4-phenylethynylpyridine ligand. In the crystal, the molecules are linked by intermolecular C—H...Cl interactions. Furthermore, C—H...π and π–π interactions also connect the molecules, forming a three-dimensional network. Hirshfeld surface analysis indicates that the most important contributions for the packing arrangement are from H...H and C...H/H...C interactions.


Author(s):  
Natwara Sutthirat ◽  
Joseph W. Ziller ◽  
Jenny Y. Yang ◽  
Zachary Thammavongsy

The reaction of Ni(TPAP)(COD) {where TPAP = [(NC5H4)CH2]3P(NC2H4)3N} with Fe(CO)5 resulted in the isolation of the title heterobimetallic NiFe(TPAP)(CO)5 complex di-μ-carbonyl-tricarbonyl[2,8,9-tris(pyridin-2-ylmethyl)-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane]ironnickel, [FeNi(C24H30N7P)(CO)5]. Characterization of the complex by 1H and 31P NMR as well as IR spectroscopy are presented. The structure of NiFe(TPAP)(CO)5 reveals three terminally bound CO molecules on Fe0, two bridging CO molecules between Ni0 and Fe0, and TPAP coordinated to Ni0. The Ni—Fe bond length is 2.4828 (4) Å, similar to that of the reduced form of the active site of NiFe hydrogenase (∼2.5 Å). Additionally, a proximal pendant base from one of the non-coordinating pyridine groups of TPAP is also present. Although involvement of a pendant base has been cited in the mechanism of NiFe hydrogenase, this moiety has yet to be incorporated in a structurally characterized synthetic mimic with key structural motifs (terminally bound CO or CN ligands on Fe). Thus, the title complex NiFe(TPAP)(CO)5 is an unique synthetic model for NiFe hydrogenase. In the crystal, the complex molecules are linked by C—H...O hydrogen bonds, forming undulating layers parallel to (100). Within the layers, there are offset π–π [intercentroid distance = 3.2739 (5) Å] and C—H...π interactions present. The layers are linked by further C—H...π interactions, forming a supramolecular framework.


2014 ◽  
Vol 70 (8) ◽  
pp. 828-832
Author(s):  
William W. Brennessel ◽  
John E. Ellis

Homoleptic 2,2′-bipyridine (bipy) metalates of iron and cobalt have been synthesized directly from the corresponding homoleptic anthracene metalates. In the iron structure, bis[([2.2.2]cryptand)potassium(I)] tris(2,2′-bipyridine)ferrate(–I) anthracene(–I), [K(C18H36N2O6)]2[Fe(C10H8N2)3](C14H10), the asymmetric unit contains one potassium complex cation in a general position, the Fe center and one and a half bipy ligands of the ferrate complex on a crystallographic twofold axis that includes the Fe atom, and one half of an anthracene radical anion whose other half is generated by a crystallographic inversion center. The cations and anions are well separated and the geometry about the Fe center is essentially octahedral. In the cobalt structure, ([2.2.2]cryptand)potassium(I) bis(2,2′-bipyridine)cobaltate(–I) anthracene hemisolvate tetrahydrofuran (THF) disolvate, [K(C18H36N2O6)][Co(C10H8N2)2]·0.5C14H10·2C4H8O, the asymmetric unit contains the cation, anion, and both cocrystallized THF solvent molecules in general positions, and one half of a cocrystallized anthracene molecule whose other half is generated by a crystallographic inversion center. The cation and anion are well separated and the ligand planes in the cobaltate anion are periplanar. Each anthracene molecule is midway between and is oriented perpendicular to a pair of symmetry-related bipy ligands such that aromatic donor–acceptor interactions may play a role in the packing arrangement. The lengths of the bonds that connect the bipy rings support the assertion that the ligands are bipy radical anions in the iron structure. However, in the case of cobalt, these lengths are between the known ranges for a bipy radical anion and a bipy dianion, and therefore no conclusion can be made from the crystallography alone. One cocrystallized THF solvent molecule in the cobalt structure was modeled as disordered over three positions with appropriate geometric and thermal restraints, which resulted in a refined component mass ratio of 0.412 (4):0.387 (3):0.201 (3).


2014 ◽  
Vol 70 (a1) ◽  
pp. C305-C305
Author(s):  
Alan Ji ◽  
Gilbert Privé

Cullin3 (Cul3) is an ubiquitin E3 ligase responsible for catalyzing the transfer of an ubiquitin moiety from an E2 enzyme to a target substrate protein. The C-terminal region of Cul3 binds RBX1/E2-ubiquitin, while, the N-terminal region interacts with various BTB domain proteins which serve as substrate adaptors. Previously, our group determined the crystal structures of the homodimeric BTB proteins SPOP and KLHL3 in complex with the N-terminal domain of Cul3, revealing the determinants responsible for the BTB/Cul3 interaction [1, 2]. A second class of BTB-domain containing proteins, the KCTD proteins, are also Cul3 substrate adaptors but these do not share many of the previously determined features for Cul3 binding. Furthermore, KCTD proteins form homotetramers and homopentamers via BTB oligomerization rather than the previously described homodimers. Despite these differences, many KCTD proteins interact with Cul3 with dissociation constants of approximately 50 nM. While the target substrates for many of the KCTD/Cul3 E3 ligase complexes are unknown, recent studies have implicated the GABAβ2 receptor as an interactor of KCTD 8, 12, 12b and 16. Here, we report the pentameric crystal structure of the KCTD9 BTB domain and our progress on the structural characterization of Cul3/KCTD/substrate complexes.


Author(s):  
Abdelhakim Laachir ◽  
Fouad Bentiss ◽  
Salaheddine Guesmi ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

In the mononuclear title complex, [Co(N3)2(C12H8N4S)2], the cobalt(II) atom is located on an inversion centre and displays an axially weakly compressed octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by N atoms of the azide anions. The thiadiazole and pyridine rings linked to the metal are almost coplanar, with a maximum deviation from the mean plane of 0.0273 (16) Å. The cohesion of the crystal is ensured by weak C—H...N hydrogen bonds and by π–π interactions between pyridine rings [intercentroid distance = 3.6356 (11) Å], forming a layered arrangement parallel to (001). The structure of the title compound is isotypic with that of the analogous nickel(II) complex [Laachiret al.(2013).Acta Cryst.E69, m351–m352].


1994 ◽  
Vol 47 (2) ◽  
pp. 391 ◽  
Author(s):  
CJ Kepert ◽  
BW Skeleton ◽  
AH White

The room-temperature single-crystal X-ray structural characterization of the title compound (tpyH2)2[Tb(OH2)8]Cl7.~2⅓H2O is recorded. Crystals are triclinic, Pī , a 17.063(5), b 16.243(3), c 7.878(3) Ǻ, α 84.78(2), β 84.39(3), γ 87.81(2)°, Z = 2 formula units; 3167 'observed' diffractometer reflections were refined by full-matrix least-squares procedures to a residual of 0.057. Notable features of interest of the compound are the 'chelation' of chloride ions by the terpyridinium cations , and the existence of a free [Tb(OH2)8]2+ cation in the presence of an abundance of chloride ions.


2014 ◽  
Vol 70 (3) ◽  
pp. m96-m97 ◽  
Author(s):  
Yuya Tsunezumi ◽  
Kouzou Matsumoto ◽  
Shinya Hayami ◽  
Akira Fuyuhiro ◽  
Satoshi Kawata

The title complex, [Co(C21H16N4)2][Co(NCS)4]·CH3OH, consists of one [Co{C(py)4}2]2+complex cation [C(py)4= tetrakis(pyridin-2-yl)methane], one [Co(NCS)4]2−complex anion and a methanol solvent molecule. In the cation, the CoIIatom is coordinated by six N atoms of two C(py)4ligands in a distorted octahedral geometry. In the anion, the CoIIatom is coordinated by the N atoms of four NCS−ligands in a distorted tetrahedral geometry. The methanol molecule is disordered and was modelled over three orientations (occupancies 0.8:0.1:0.1). There are two weak hydrogen-bond-like interactions between the methanol solvent molecule and NCS−ligands of the anion [O...S = 3.283 (3) and 3.170 (2) Å].


2015 ◽  
Vol 71 (8) ◽  
pp. m152-m153 ◽  
Author(s):  
Liubov M. Lifshits ◽  
Charles Campana ◽  
Jeremy K. Klosterman

The structure of the polymeric title compound, {[Zn2(C20H11NO4)2(C3H7NO)2(CH3OH)]·C3H7NO}n, comprises carbazolylisophthalate moieties connecting dimetallic tetracarboxylate zinc secondary building units (SBUs) parallel to [100] and [010], leading to a layer-like arrangement parallel to (001). Each SBU consists of two Zn atoms in slightly distorted tetrahedral and octahedral coordination environments [Zn...Zn = 3.5953 (6) Å]. Three carboxylate groups bridge the two Zn atoms in a μ2-O:O′ mode, whereas the fourth coordinates through a single carboxylate O atom (μ1-O). The O atoms of two dimethylformamide (DMF) and one methanol molecule complete the Zn coordination spheres. The methanol ligand interacts with the noncoordinating DMF moleculeviaan O—H...O hydrogen bond of medium strength. Carbazoles between the layers interdigitate through weak C—H....π interactions to form a laminar solid stacked along [010]. Two kinds of C—H...π interactions are present, both with a distance of 2.64 Å, between the H atoms and the centroids, and a third C—H...π interaction, where the aromatic H atom is located above the carbazole N-atom lone pair (H...N = 2.89 Å). Several C—H...O interactions occur between the coordinating DMF molecule, the DMF solvent molecule, and ligating carboxylate O atoms.


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