Crystal Structure Studies towards the Synthesis and Applications of N-heterocyclic Carbene–Metal Complexes Derived from [2.2]Paracyclophane

2015 ◽  
Vol 68 (10) ◽  
pp. 1472 ◽  
Author(s):  
Wenzeng Duan ◽  
Yudao Ma ◽  
Yanmin Huo ◽  
Qingxia Yao

The crystal structures of six planar chiral N-heterocyclic carbene (NHC) precursors and one NHC–Rh complex derived from [2.2]paracyclophane were described. The NHC–metal complexes were prepared to examine their catalytic activities toward the Rh-catalyzed asymmetric addition of phenylboronic acid to 1-naphthaldehyde. The results were correlated to the single-crystal crystallographic studies. The novel NHC precursor 5 can achieve high catalytic activity in the asymmetric addition of phenylboronic acid to 1-naphthaldehyde.

2019 ◽  
Vol 7 (21) ◽  
pp. 13142-13148 ◽  
Author(s):  
Liang-Liang Yang ◽  
Hong-Juan Wang ◽  
Juan Wang ◽  
Yu Li ◽  
Wen Zhang ◽  
...  

A new graphdiyne-based carbon material was synthesized as an ideal substrate for electroless deposition and stabilization of sub-nanometric Pd catalysts, which showed extremely high catalytic activities for the reduction of nitroarenes and Suzuki coupling reactions.


Author(s):  
William W. Brennessel ◽  
John E. Ellis

The reaction of the [K(18-crown-6)(thf)2]1+ (thf is tetrahydrofuran) salt of bis(anthracene)ferrate(−1), or [Fe(C14H10)2]−, with 2,6-dimethylphenyl isocyanide (CNXyl) in thf resulted in the formation of two new iron isocyanide complexes, namely, [(1,2,3,4-η)-anthracene]tris(2,6-dimethylphenyl isocyanide)iron, [Fe(C14H10)(C9H9N)3] or [Fe(1,2,3,4-η-C14H10)(CNXyl)3], and {5,6-bis(2,6-dimethylanilino)-3-(2,6-dimethylphenyl)-1,2,7-tris[(2,6-dimethylphenyl)imino]-3-azoniahept-3-ene-1,4,7-triido}tris(2,6-dimethylphenyl isocyanide)iron tetrahydrofuran disolvate, [Fe(C54H56N6)(C9H9N)3]·2C4H8O or [Fe(C54H56N6)(CNXyl)3]·2C4H8O, which were characterized by single-crystal X-ray diffraction. The former is likely an intermediate along the path to the known homoleptic [Fe(CNXyl)5], while the latter contains a tridentate ligand that is formed from the `coupling' of six CNXyl ligands. A third crystal structure from this reaction, (7-methylindol-1-ido-κN)(1,4,7,10,13,16-hexaoxacyclooctadecane-κ6 O)potassium, [K(C9H8N)(C12H24O6)] or [K(C9H8N)(18-crown-6)], contains a 7-methylindol-1-ide anion, in which one CNXyl ligand has shed a proton during its reductive cyclization.


1979 ◽  
Vol 34 (3) ◽  
pp. 434-436 ◽  
Author(s):  
A. Müller ◽  
S. Pohl ◽  
M. Dartmann ◽  
J. P. Cohen ◽  
J. M. Bennett ◽  
...  

Abstract The novel tri-nuclear metal-sulfur cluster [Mo3S(S2)6]2- can be obtained as its ammonium salt by the reaction of a Moiv containing aqueous solutions with polysulfide. Its crystal and molecular structure has been determined by a single crystal X-ray study. The crystals are monoclinic (space group Cm, with a = 11.577(6) Å, b = 16.448(7) Å, c = 5.716(2) Å, β = 117.30(3)°, V = 967.2 Å3 , Z = 2, dexptl. = 2.54(2) g/cm3 , dcal = 2.54 g/cm3). The structure consists of isolated [Mo3S(S2)6]2- units, with three Mo atoms at the vertices of a triangle. There are bridging as well as terminal S22--ligands lying above and below the Mo3-plane (bond distances: Mo-Mo = 2.722 Å, Mo-S(terminal) = 2.435, Mo-S(bridging) = 2.452, Mo3-S = 2.353(4) Å and S-S = 2.04 Å (mean values)).


1984 ◽  
Vol 39 (6) ◽  
pp. 705-712 ◽  
Author(s):  
Kurt O. Klepp ◽  
Günther Eulenberger

AbstractThe isostructural compounds Tl4TiS4, Tl4SnS4 and Tl4TiSe4 crystallize in the monoclinic system, space group P21/c with a = 8.328, b = 8.191, c = 15.248 Å, β = 104.53°; a = 8.395, b = 8.280, c = 15.398 A, ft = 103.69°, and a = 8.517, b = 8.389, c = 15.672 Å, β = 103.50°, respectively. There are four formula units in the unit cell. The crystal structures were determined and refined from single crystal diffractometer data. They are characterized by isolated tetrahedral thioanions which are connected with each other by Tl+ ions. The mean bond lengths are Ti-S = 2.26 Å, Sn-S = 2.40 Å and Ti -Se = 2.38 Å. The Tl atoms are surrounded by six and seven chalcogen atoms, respectively, in an irregular and polar arrangement, thus indicating stereochemical activity of the lone electron pair of the Tl+ ions. Tl-S distances vary from 2.93 to 3.98 Å, Tl-Se distances from 3.03 to 3.96 Å. The Tl atoms have nearest Tl neighbours at distances ranging from 3.46 to 3.65 Å. The crystal structure can be described as built from pseudotetragonal slabs oriented parallel to (001) which contain the cations and the tetrahedral anions. It is shown that a similar description is valid also for the crystal structures of Tl4GeS4 [1] and Na4SnS4 [2, 3].


Author(s):  
M. L. Fornasini ◽  
A. Saccone

AbstractThe crystal structures of two phases in the neodymium-gold system were determined by single crystal X-ray diffractometer methods,


1992 ◽  
Vol 47 (12) ◽  
pp. 1687-1692 ◽  
Author(s):  
Heinz Dieter Lutz ◽  
Peter Kuske ◽  
Arno Pfitzner ◽  
Hermann-Josef Steiner

The crystal structure of the novel pink Li5CrCl8 oC28 has been determined by both single crystal X-ray and neutron powder studies. The title compound crystallizes in a hitherto unknown structure type (space group C mmm, Z = 2). The final R values are R = 3.4% (715 independent reflections with I > 3aI) and Rwp = 11.5%, respectively (a = 1019.79(3), b = 723.94(2) and c = 726.16(3) pm). The structure consists of edge-connected Li(l)Cl6 and alternating edge-connected Li(2)Cl6 and CrCl6 octahedra, respectively. It is related to the NaCl super structure SnMn2S4 type. IR and Raman spectra as well as symmetry coordinates are given and discussed in terms of CrCl6 and LiCl6 breathing modes.


1990 ◽  
Vol 43 (10) ◽  
pp. 1697 ◽  
Author(s):  
GA Bowmaker ◽  
PC Healy ◽  
LM Engelhardt ◽  
JD Kildea ◽  
BW Skelton ◽  
...  

The crystal structures of [Cu(Pme3)4]X (X = Cl , Br, I) and of [M(PPh3)4] [PF6] (M = Cu, Ag) have been determined by single-crystal X-ray diffraction methods at 295 K. The former compounds contain nearly tetrahedral [Cu(PMe3)4]+ ions on sites of m symmetry with mean Cu-P bond lengths of 2.270, 2.271 and 2.278 Ǻ for X = Cl , Br and I respectively. The latter compounds contain [M(PPh3)4]+ ions on sites of 3 symmetry. In the M =Ag complex the coordination environment is close to tetrahedral, but in the M =Cu complex the length of the axial Cu-P bond [2.465(2)Ǻ] is significantly shorter than that of the off-axis bonds [2.566(2)Ǻ]. Possible reasons for this are discussed.


2006 ◽  
Vol 2006 ◽  
pp. 1-11 ◽  
Author(s):  
Michael Devereux ◽  
Malachy McCann ◽  
Denis O'Shea ◽  
Mark O'Connor ◽  
Eileen Kiely ◽  
...  

2,2-dimethylpentanedioic acid (2dmepdaH2) and 3,3-dimethylpentanedioic acid (3dmepdaH2) reacted with copper(II) acetate to give [Cu(2dmepda)(H2O)3]2(1) and [Cu(3dmepda)(H2O)3]2(2). Reaction of (1) and (2) with 1,10-phenanthroline and 2,2′-bipyridine yielded [Cu(2dmepda)(phen)(H2O)]20.5phen (3), [Cu(2dmepda)(bipy)(H2O)]2(4), [Cu(2dmepda)(bipy)(EtOH)]2⋅2EtOH(4A), [Cu(3dmepda)(phen)(H2O)]2(5), and [Cu(3dmepda)(bipy)(H2O)]2⋅(6). The structures of (4A) and (6) each consists of a [Cu(bipy)(dicarboxylate)(solvent)]2dimer. The superoxide dismutase (SOD) mimetic activity of the novel copper complexes and their manganese analogues was investigated. The dimethyl sulphoxide(DMSO) soluble complexes (1)–(4) and (6) were assessed for their cancer chemotherapeutic potential towards hepatocellular carcinoma and kidney adenocarcinoma cell lines. The 1,10-phenanthroline containing complex [Cu(2dmepda)(phen)(H2O)]20.5phen (3) was the most potent with activity that compares well to that ofcisplatin.


RSC Advances ◽  
2015 ◽  
Vol 5 (95) ◽  
pp. 77948-77957 ◽  
Author(s):  
Vignesh Arumugam ◽  
Werner Kaminsky ◽  
Dharmaraj Nallasamy

Four new palladium(ii) complexes featuring ONO pincer type hydrazone ligands were synthesized and characterized by spectroscopic and single-crystal XRD analysis. Utility of these complexes to catalyze C–C bond formation in quinoline scaffolds were assessed.


2009 ◽  
Vol 64 (8) ◽  
pp. 985-988 ◽  
Author(s):  
Jian-Qiang Wang ◽  
Thomas F. Fässler

The cobalt complex [{K(18-crown-6)}2(C5H5)]- [Co(C8H12)2]・(THF)2 (3) has been synthesized and characterized by X-ray single-crystal structure determination. The crystal structure of Co(C8H12)(C8H13) (2) has been reinvestigated and compared with the structure of 3. The 1,5-cyclooctadiene (C8H12) and C8H13 ligands are coordinated in an η4 and η3 fashion, respectively. The cyclopentadienyl anion in [{K(18-crown-6)}2(C5H5)]+ in 3 is η5-coordinated to the two crown ether-encapsulated potassium cations


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