Synthesis and Structural Characterization of Palladium Dicarbene Complexes Bearing Labile Co-Ligands

2009 ◽  
Vol 62 (9) ◽  
pp. 983 ◽  
Author(s):  
Han Vinh Huynh ◽  
Hui Xian Seow

Dicarbene complexes [Pd(OAc)2(diNHC)] (2), [Pd(O2CCF3)2(diNHC)] (3), and [Pd(CNCH3)2(diNHC)](SO3CF3)2 (4) bearing labile acetato, fluoroacetato, and acetonitrile co-ligands have been synthesized via metathesis reaction of the respective precursor [PdBr2(diNHC)] (1) with Ag-salts. All complexes are stable towards air and moisture and have been fully characterized by spectroscopic and spectrometric methods. Notably and in comparison to diphosphine analogues, they resist ligand disproportionation in solution. Their molecular structures have also been determined by single crystal X-ray diffraction. A preliminary catalytic study showed low activity in the hydroamination reaction, but revealed an interesting co-ligand influence.


2015 ◽  
Vol 70 (3) ◽  
pp. 165-169 ◽  
Author(s):  
Gao-Feng Wang

AbstractThe synthesis of two new copper(II) complexes with benzimidazole type ligands, Cu(tta)2(L1)2 (1) and Cu(tta)2(L1) (2) (where L1 is 3-(4-(1H-benzo[d]imidazol-1-yl)-4-methoxy phenyl)-1-phenylprop-2-en-1-one; tta is 2-thenoyltrifluoroacetonate), are reported. Their structures have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. The copper(II) ion of 1 is in a distorted octahedral environment, while that of 2 is in a distorted square-pyramidal environment. In both cases, the donor atoms are provided by oxygen atoms of the tta ligands and nitrogen atoms of the L1 ligands.



2014 ◽  
Vol 67 (7) ◽  
pp. 1063 ◽  
Author(s):  
Rafael Fernández-Galán ◽  
Juan-Antonio Navarro ◽  
Fernando Carrillo-Hermosilla ◽  
Antonio Antiñolo ◽  
Isabel López-Solera ◽  
...  

The new lithium guanidinate salt [Li{μ-κ1,κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(THF)]2 (1) was obtained by the reaction of HNMe2 with n-BuLi and further reaction with the asymmetric carbodiimide EtN=C=N-t-Bu. Guanidinate-supported zirconium complexes [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(μ-Cl)Cl2]2 (2), [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}3Cl] (4), [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}2(η5-C5H5)Cl] (5) and [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}(η5-C5H5)2Cl] (6) were prepared. Complexes 2, 4, and 6 were synthesized by the metathesis reaction of ZrCl4 or [ZrCl2(η5-C5H5)2] with 1. The previously described complex [Zr{κ2,N,N′-(NEt)(N-t-Bu)CNMe2}2Cl2] (3), which was prepared by the insertion reaction of EtN=C=N-t-Bu into a metal–amido bond of [Zr(NMe2)2Cl2(THF)2], allowed the new complex 5 to be obtained by reaction with NaC5H5. All of the new complexes were characterized spectroscopically and the molecular structures of 1, 4, and 6 were determined by single-crystal X-ray diffraction.



2015 ◽  
Vol 70 (7) ◽  
pp. 491-496 ◽  
Author(s):  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Eduardo E. Castellano ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

AbstractThree new acesulfamate salts, NaC4H4NO4S, RbC4H4NO4S and CsC4H4NO4S, were prepared by reactions in aqueous solutions and thoroughly characterized. Their crystal and molecular structures were determined by single crystal X-ray diffraction methods. They crystallize in the monoclinic space group P21/a with a = 7.2518(2), b = 8.9414(4), c = 10.5929(4) Å, β = 99.951(3)°, V = 676.52(4) Å3 for the Na salt; a = 7.4663(3), b = 9.6962(4), c = 10.4391(4) Å, β = 95.150(3)°, V = 752.68(5) Å3 for the Rb salt and a = 7.5995(4), b = 9.9439(4), c = 10.8814(6) Å, β = 91.298(5)°, V = 822.08(7) Å3 for the Cs salt, and Z = 4 molecules per unit cell. The three compounds are isotypic to each other and to the previously reported potassium salt. The metal ions are in irregular polyhedral coordination with six neighboring acesulfamate anions through their nitrogen and carbonyl and sulfoxide oxygen atoms. The FTIR spectra of the compounds were also recorded and are briefly discussed.



2019 ◽  
Vol 16 (33) ◽  
pp. 516-523
Author(s):  
G. E. DELGADO ◽  
L. M. BELANDRIA ◽  
M. GUILLEN ◽  
A.. J. MORA ◽  
L. E. SEIJAS

2-amino-2-oxoacetic acid, carbamoyl formic acid, or oxamic acid is an active pharmaceutical ingredient (API) of great importance mainly because is an inhibitor of lactic dehydrogenase (LDH). It acts as an inhibitor to the metabolic pathways of the tumor cells and exhibited significant anticancer activity against nasopharyngeal carcinoma (NPC) cells in vitro and can be considered as a potential drug for the treatment of type 2 diabetes. Also, this compound could be used as a building block in the design of supramolecular architectures based on hydrogen bonds through the complimentary hydrogen-bond functionalities of the carbonyl and amide functional groups present. Single-crystal X-ray diffraction is the most powerful technique for crystal structure determination of small molecules. However, for several materials, including oxamic acid, it could be complicated to grow single crystals of suitable size and quality that make them appropriated to structure analysis. For this reason, the structural study was conducted with powder X-ray diffraction which is a process significantly more challenging than structure determination from single-crystal data. Oxamic acid has been characterized by FT-IR and NMR spectroscopic techniques, thermal TGA-DSC analysis, semi-empirical PM7 calculations, and X-ray powder diffraction. The title compound crystallizes in the monoclinic system with space group Cc, Z=4, and unit cell parameters a= 9.4994(4) Å, b= 5.4380(2) Å, c= 6.8636(3) Å, b= 107.149(2)°, V= 338.79(2) Å3. The molecule has a trans conformation. The molecular structure and crystal packing are stabilized mainly by intra- and intermolecular O--H···O and N--H···O hydrogen bonds. The structural characterization of this type of API compound is important to understand its mechanisms of action due to its considerable biological effects. In particular, for oxamic acid, this structural study would allow subsequent examination of its medicinal properties as an antitumor and antidiabetic agent.



1987 ◽  
Vol 40 (11) ◽  
pp. 1881 ◽  
Author(s):  
AJ Canty ◽  
LM Engelhardt ◽  
PC Healy ◽  
JD Kildea ◽  
NJ Minchin ◽  
...  

Reaction of 2,6-bis[l-phenyl-1-(pyridin-2-yl)ethyl]pyridine, L, with copper(1) chloride, bromide, and iodide in acetonitrile solution has been shown to yield salts, structurally characterized by single-crystal X-ray diffraction methods as [( MeCN ) CuL ]+ [ ClCuCl ]-, (1), [( MeCN ) CuL ]+2 [XCuX2CuX]2-, X = Br (2), I (3) (both isomorphous ), all as yellow needles, and a form of (3), orange blocks, as the hemiacetonitrile solvate, (4), [( MeCN ) CuL ]+2 [IcuI2Cul]2-. MeCN . The same cation is common to all four species, containing four-coordinate copper(r), with L as meso -tridentate ligand; in (4), the most precisely defined example, Cu-N( MeCN ) is 1.919(5) �, the shortest copper(1) acetonitrile distance known, while Cu-N(L) are 2.065(5)-2.073(5) �. The reason for non-formation of species of the type [ LCuX ] appears to lie in the tridentate ligand conformation which permits coordination of acetonitrile but not larger halide species.



1996 ◽  
Vol 49 (12) ◽  
pp. 1273 ◽  
Author(s):  
AL Maclean ◽  
GJ Foran ◽  
BJ Kennedy ◽  
P Turner ◽  
TW Hambley

The structure of 5,10,15,20-tetraphenylporphinatonickel(II) ([Ni( tpp )]) has been studied by both X-ray diffraction (powder and single-crystal methods) and EXAFS. The bond lengths obtained from analysis of the EXAFS agree, within standard deviations, with those obtained from the X-ray diffraction studies. The Ni-N bond length of 1.93(1) Ǻ agrees especially well with the value of 1.931(2) Ǻ obtained from the single-crystal analysis. The powder X-ray diffraction pattern, collected by using synchrotron radiation, is presented.



2013 ◽  
Vol 68 (1) ◽  
pp. 91-94 ◽  
Author(s):  
Anja Molter ◽  
Fabian Mohr

In an attempt to prepare the tris(selenoureato)gallium(III) complex [Ga(4-O2NC6H4C(O)NC(Se)NEt2)3] from the reaction of the nitro-substituted acylselenourea 4-O2NC6H4C(O)NHC(Se)NEt2 with [Ga(NO3)3] in EtOH we obtained a crystalline compound from a CH2Cl2 solution which was identified as the bis(selenoureato)gallium(III)chlorido complex [GaCl(4- O2NC6H4C(O)NC(Se)NEt2)2] by single-crystal X-ray diffraction. This compound is a rare example of a metal complex containing chelating selenoureato ligands in a trans arrangement.



2018 ◽  
Vol 96 (6) ◽  
pp. 570-577 ◽  
Author(s):  
Alina M. Secara ◽  
Justin F. Binder ◽  
Ala’aeddeen Swidan ◽  
Charles L.B. Macdonald

A series of germanium(II) and tin(II) bromide polyether complexes have been synthesized. Specifically, [GeBr([15]crown-5)][GeBr3], [GeBr([18]crown-6)][GeBr3], [GeBr(triglyme)][GeBr3], [GeBr(tetraglyme)][GeBr3], [SnBr([18]crown-6)][SnBr3], [Sn([15]crown-5)2][SnBr3]2, [SnBr(triglyme)][SnBr3], and [SnBr(tetraglyme)][SnBr3] have been fully characterized including by single crystal X-ray diffraction. The synthesis of [GeBr(dibenzo[24]crown-8)][GeBr3] and [GeCl(dibenzo[24]crown-8)][GeCl3] are also reported, along with the crystal structure of the latter’s water adduct, which features a water molecule adjacent to the GeCl+ ion within the cavity of the crown ether.



2019 ◽  
Vol 74 (11-12) ◽  
pp. 857-860
Author(s):  
Hai-Wei Kuai ◽  
Xiao-Hong Zhu ◽  
Ding-Yun Jiang ◽  
Xiao-Chun Cheng ◽  
Deng-Hao Li

Abstract1,3,5-Tri(1H-imidazol-4-yl)benzene (H3L) reacts with Ni(ClO4)2 · 6H2O under hydrothermal conditions at T = 100°C to yield a new complex: [Ni(H2L)2] · 5.5H2O (1). The product is characterized by single crystal and powder X-ray diffraction, infrared spectroscopy, and elemental and thermogravimetric analyses. Complex 1 crystallizes in the monoclinic space group C2/c and exhibits a binodal (3,6)-connected 2D kgd network structure with (43)2(46.66.83) topology.



1985 ◽  
Vol 38 (5) ◽  
pp. 669 ◽  
Author(s):  
PC Healy ◽  
C Pakawatchai ◽  
AH White

The crystal structure of [C13H10N] [CuCl3(C13H9N)].H2O(C13H9N ≡ acridine ) has been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to a residual of 0.037 for 1942 independent 'observed' reflections. Crystals are triclinic, Pī , a 16.27(2), b 10.080(8), c 7.236(5) Ǻ, α 88.85(6), β 82.68(8), γ 81.12(9)°, Z 2. The metal atom stereochemistry is unusual, being of pseudo-m symmetry; one of the chlorine atoms is coplanar with the copper and the acridine [Cu- Cl 2.237(2) Ǻ, N-Cu- Cl 143.5(1)°], with the other two disposed to either side of that plane [Cu- Cl 2.252(3), 2.243(2) Ǻ; Cl-Cu-Cl 145.62(7)°]. Cu-N is 2.018(5) Ǻ.



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