scholarly journals M–H–BR3 and M–Br–BR3 interactions in rhodium and nickel complexes of an ambiphilic phosphine–thioether–borane ligand

2018 ◽  
Vol 96 (5) ◽  
pp. 484-491 ◽  
Author(s):  
Bradley E. Cowie ◽  
David J.H. Emslie
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Nickel Complexes ◽  
Planar Geometry ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Square Planar ◽  
Hydride Ligand

Reaction of [Rh(μ-Cl)(CO)(TXPB)] (1; TXPB = 2,7-di-tert-butyl-5-diphenylboryl-4-diphenylphosphino-9,9-dimethylthioxanthene) with NaBH4 yielded square planar [Rh(μ-H)(CO)(TXPB)] (2) in which the hydride ligand bridges between rhodium and the borane unit of TXPB. The Rh–H, Rh–B, and Rh–Cipso distances are short at 1.84(5), 2.456(6), and 2.568(5) Å, respectively, whereas the B–H bond, 1.59(6) Å, falls at the longer end of the usual range. Compound 2 is compared with the previously reported series of rhodium TXPB complexes: [RhX(CO)(TXPB)] {X = F (3), Cl (1), Br (4), I (5)}. Compound 4 in this series features the only crystallographically characterized example of an M–Br–BR3 interaction, and to expand this area, [NiBr(μ-Br)(TXPB)] (6) was prepared via the reaction of [NiBr2(dme)2] (dme = 1,2-dimethoxyethane) with TXPB. An X-ray crystal structure of light purple 6 revealed a square-planar geometry with a strong B–Br interaction {B–Br = 2.311(6) Å; ∑(C–B–C) = 344.5(7)°}. An 11B NMR chemical shift of 23 ppm was observed for 6, indicating that an appreciable B–Br interaction is maintained in solution. No signals were observed in the 31P{1H} NMR spectrum at room temperature, whereas a broadened 31P signal was observed at −20 °C, evolving into a sharp singlet at −67 °C. This behaviour suggests that at room temperature, square planar 6 exists in equilibrium with a paramagnetic tetrahedral isomer, present at a level below that detectable through Evans magnetic measurements.

Das 7,8-Benzo-5-chloro-1,4,4-trimethyl-1-aza-4-azonia-6,9-dioxa-5 λ5-phosphaspiro[4.4]nonanyl-Kation: Röntgenstrukturanalyse und temperaturabhängige 1H-NMR-Spektren: The 7, 8-Benzo-5-chloro-1,4,4-trimethyl-1-aza-4-azonia-6,9-dioxa-5 λ).5-phosphaspiro[4.4]nonanyl Cation: X-Ray Crystal Structure Determination and Variable 1H NMR Spectra

1992 ◽  
Vol 47 (6) ◽  
pp. 755-759 ◽  
Author(s):  
Thomas Kaukorat ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
1H Nmr ◽  
Nmr Spectra ◽  
Crystal Structure Analysis ◽  
Acceptor Interaction ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Trigonal Bipyramidal ◽  
Donor Acceptor

The 1H NMR spectrum of the spirophosphorane 3 at room temperature indicates dynamic behaviour of the cation. The low-temperature 1H NMR spectra of 3 exhibit two sets of doublets for the protons of the diastereotopic N(CH3)2 groups. The free enthalpy of activation for the dynamic process was determined (58.6 KJ/mole). In the reaction of 3 with sodium tetraphenylborate the crystalline compound, 4, involving the non-coordinating anion, [B(C6H5)4]-, was obtained. The X-ray crystal structure analysis of 4 reveals the presence of a five-membered ring, formally as a result of intramolecular donor-acceptor interaction between the nitrogen atom of the N(CH3)2 group and phosphorus. The geometry at phosphorus deviates somewhat from ideal trigonal bipyramidal.

Homonuclear PdII and PtII and heteronuclear PdII-AuI and PtII-AuI complexes of a tripod triphosphine ligand: synthesis, characterization and reactions with molecules of biological relevance

2000 ◽  
Vol 53 (8) ◽  
pp. 635 ◽  
Author(s):  
Paloma Sevillano ◽  
Abraha Habtemariam ◽  
M. Inés García Seijo ◽  
Alfonso Castiñeiras ◽  
Simon Parsons ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Partial Oxidation ◽  
Bond Cleavage ◽  
Planar Geometry ◽  
Conductivity Measurements ◽  
Initial Attack ◽  
X Ray ◽  
Square Planar ◽  
Linear Geometry

Complexes of the type Pd(tripod)X2 [tripod = MeC(CH2PPh2)3; X = Cl (1), Br (2), I (3)] and Pt(tripod)X2 [X = Cl (4), Br (5), I (6)] have been synthesized. In these complexes tripod acts as a bidentate chelating ligand. The uncoordinated phosphorus atom can bind to AuI to form the bimetallic complexes PdAu(tripod)X3 [X = Cl (7), Br (8), I (9)] and PtAu(tripod)X3 [X = Cl (10), Br (11), I (12)]. Complexes (1)–(12) have been characterized by microanalysis, f.a.b. mass spectrometry, i.r. spectroscopy, 31P and 195Pt n.m.r. spectroscopies, and conductivity measurements. The structures of complexes (1), (4) and (11), as well as that of the unusual complex Cl2Pt(tripod)AuBr0.5Cl0.5 (13), isolated from reaction of Pt(tripod)Br2 (5), and [Au(thiodiglycol)Cl], have been determined. All complexes show square-planar geometry for PdII or PtII and linear geometry for AuI. The X-ray crystal structure of (1) showed partial oxidation of the dangling phosphorus of the ligand in 50% of the molecule distributed randomly over the lattice. Reactions of complex (4), Pt(tripod)Cl2, with the tripeptide glutathione (GSH) showed the formation of [Pt2(tripod)2(GS-µ–S)2]2+ (15a). No reaction with N-acetyl-L-methionine (AcMet) or guanosine 5´-monophosphate (5´-GMP) was observed. Reactions of [Pt(tripod–O)(ONO2)2] (14) with GSH resulted in the formation of [Pt2(tripod–O)2(GS-µ-S)2]2+ (15b). Displacement of the S-containing molecules by 5´-GMP in the presence of AuI, via Pt–S bond cleavage, was observed for complex (15b). PtAu(tripod)Cl3 (10) reacted with GSH, with initial attack on the AuI centre.

scholarly journals Crystal structure of [2,13-bis(acetamido)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane-κ4 N]silver(II) dinitrate from synchrotron X-ray data

2018 ◽  
Vol 74 (4) ◽  
pp. 461-464 ◽  
Author(s):  
Dohyun Moon ◽  
Jong-Ha Choi
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Planar Geometry ◽  
Nitrate Anion ◽  
Asymmetric Unit ◽  
Weakly Bound ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Square Planar ◽  
Nitrate Anions

The asymmetric unit of the title compound, [Ag(C24H46N6O2)](NO3)2 [C24H46N6O2 is (5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane-2,13-diyl)diacetamide, L], consists of one independent half of the [Ag(C24H46N6O2)]2+ cation and one nitrate anion. The Ag atom, lying on an inversion centre, has a square-planar geometry and the complex adopts a stable trans-III conformation. Interestingly, the two O atoms of the pendant acetamide groups are not coordinated to the AgII ion. The longer distance of 2.227 (2) Å for Ag—N(tertiary) compared to 2.134 (2) Å for Ag—N(secondary) may be due to the effects of the attached acetamide group on the tertiary N atom. Two nitrate anions are very weakly bound to the AgII ion in the axial sites and are further connected to the ligand of the cation by N—H...O hydrogen bonds. The crystal packing is stabilized by hydrogen-bonding interactions among the N—H donor groups of the macrocycle and its actetamide substituents, and the O atoms of the nitrate anions and of an acetamide group as the acceptor atoms.

scholarly journals Ni(II) complexes with thioether-functionalized silylamide ligands. Synthesis and crystal structures of [Ni{Me2Si(N-C6H4-2-S-t-Bu)2}], [Ni{Ph2Si(N-C6H4-2-SMe)2}] and [Ni{Ph2Si(N-C6H4-2-SPh)2}]

2019 ◽  
Vol 74 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Ralf Albrecht ◽  
Phil Liebing ◽  
Uwe Morgenstern ◽  
Christoph Wagner ◽  
Kurt Merzweiler
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Structures ◽  
Nickel Complexes ◽  
Subsequent Reaction ◽  
X Ray ◽  
Bond Lengths ◽  
Tetradentate Ligands ◽  
Square Planar ◽  
Structure Determinations

AbstractThioether-functionalized aminosilanes R2Si(NH-C6H4-2-SR′)2 with R=Me, Ph and R′=t-Bu, Me, Ph were synthesized from the corresponding dichlorosilanes R2SiCl2 and lithiated aniline derivatives LiNH-C6H4-2-SR′. Treatment of the functionalized aminosilanes R2Si(NH-C6H4-2-SR′)2 with two eq. of n-BuLi and subsequent reaction with nickel(II) halides NiX2 (X=Cl, Br) or [Ni(acac)2(TMEDA)] led to the formation of the Ni(II) complexes [Ni{R2Si(N-C6H4-2-SR′)2}]. The X-ray single-crystal structure determinations of the nickel complexes revealed that the thioether-functionalized silylamides R2Si(NC6H4-2-SR′)22− act as tetradentate ligands. The nickel atoms exhibit a distorted square-planar coordination with Ni–N and Ni–S bond lengths in the range of 186.4(3)–186.9(2) pm and 217.5(1)–221.5(1) pm, respectively.

Synthesis, Crystal Structures and Characterization of a New Antitumor Cu(II) Complex with N-sulfonamide Ligand

2018 ◽  
Vol 69 (6) ◽  
pp. 1407-1410
Author(s):  
Adriana Corina Hangan ◽  
Alexandru Turza ◽  
Roxana Liana Stan ◽  
Luminita Simona Oprean
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Metal Ion ◽  
Planar Geometry ◽  
X Ray ◽  
Magnetic Methods ◽  
Square Planar ◽  
Ft Ir

A new Cu(II) complex with N-sulfonamide ligand, [Cu(N-(5-(4-methylphenyl)-[1,3,4]-thiadiazole-2-yl)-toluenesulfonamidate)4]((CH3)2NH2+)2(complex) has been synthesized and characterized. The X-ray crystal structure of the complex has been determined. The Cu(II) ion is four-coordinated, forming a CuN4 chromophore. The ligand acts as monodentate, coordinating the metal ion through a single Nthiadiazole atom. The complex has a square planar geometry. The characterization of the complex has been studied by FT-IR, electronic, EPR spectroscopic and magnetic methods.

Crystal structure of Diaqua(1,10-phenanthroline)copper(II) sulfate

1984 ◽  
Vol 37 (5) ◽  
pp. 1111 ◽  
Author(s):  
PC Healy ◽  
JM Patrick ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Copper Atom ◽  
Title Compound ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Axial Coordination ◽  
Square Planar

The crystal structure of the title compound, [Cu(OH2)2(phen)] (SO4) (phen = 1,10-phenanthroline), has been determined by single-crystal X-ray diffraction methods at room temperature, being refined by full matrix least-squares methods to a residual of 0.033 for 1445 'observed' reflections. Crystals are monoclinic, C2/c, a 14.883(8), b 13.843(9), c 7.019(4) �, β 108.60(4)�, Z 4. As in a number of other copper(II) and nickel(II) derivatives with (CuL4)(SO4) stoichiometry, the pseudo-square planar copper environments [Cu-N,O: 2.009(2), 1.970(2) � in the present case] are bridged through the two axial coordination positions by sulfate groups: O.SO2.O[Cu(OH2)2(phen)]O.SO2.0, etc. to give a linear polymeric array [Cu-O(SO4), 2.468(3) �]; a crystallographic twofold axis passes through the copper atom.

Elucidation of the structures of the hydridothiolato complexes WH(SC6H2Pri3-2,4,6)3(L)(PMe2Ph), L = PMe2Ph or pyridine, by NMR and X-ray techniques

1995 ◽  
Vol 73 (7) ◽  
pp. 1092-1101 ◽  
Author(s):  
Timothy E. Burrow ◽  
Alan J. Lough ◽  
Robert H. Morris ◽  
Raymond L. Richards
Keyword(s):  
X Ray Diffraction ◽  
Pyridine Ligand ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Pyridine Ligands ◽  
Trigonal Bipyramidal ◽  
Hydride Ligand ◽  
Nmr Methods

Measurement of the T1 values of the 31P nuclei in the unusual capped trigonal bipyramidal complexes WH(tipt)3(PMe2Ph)2 (1, tipt = SC6H2Pri3-2,4,6) and W(2H)(tipt)3(PMe2Ph)2 allows the determination of the phosphorus–hydride distance of 2.2 ± 0.2 Å and the P-W-H angle of about 62 ± 7°. An approximate location of the hydride on an S2P face is proposed on the basis of steric interactions. The crystal structure of WH(tipt)3-(NC5H5)(PMe2Ph) (2) is reported; the WS3NP core consists of a distorted trigonal bipyramidal system with the phosphine and pyridine ligands axial and the thiolate ligands equatorial. The hydride ligand was not located by X-ray diffraction but can be positioned on an open S2P face at an angle P-W-H of about 65°. The small P-W-H angle results in large 2J(H,P) couplings for 1 and 2. The 1H NMR spectrum of complex 2 is assigned by use of NOE and homodecoupling NMR methods. This complex has the same crowded structure in solution as in the crystalline state. The pyridine ligand, which is sandwiched between two tipt aryl groups, is hindered from rotating around the W—N bond. Keywords: molybdenum, tungsten, thiolate, hydride, NMR, NOE.

Diels-Alder Reactions of Cyclopentadiene with Several Ferrocenyl- and η6-Phenyltricarbonylchromium Analogues of Chalcone. Catalytic Effect of SiO2

1996 ◽  
Vol 61 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Monika Prokešová ◽  
Grety Rihs ◽  
Štefan Toma
Keyword(s):  
Good Yield ◽  
Room Temperature ◽  
Catalytic Effect ◽  
Alder Reaction ◽  
Diels Alder ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Diels Alder Reaction ◽  
Electron Withdrawing Group

The Diels-Alder reaction of cyclopentadiene with eight electron deficient dienophiles was studied. The reaction was performed at room temperature using silica gel as an inorganic support, without solvent. Only one of the two possible Diels-Alder adducts was isolated in moderate to good yield. The structure of products with endo-oriented electron-withdrawing group was proved by 1H NMR spectrum and in one case (9b) by X-ray analysis.

Tetraalkylammonium Tetrachlorothallates (III); X-Ray, 35Cl-NQR, and 1H-NMR Studies

1991 ◽  
Vol 46 (9) ◽  
pp. 777-784 ◽  
Author(s):  
Marco Lenck ◽  
Shi-qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Ii ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Nmr Studies ◽  
X Ray ◽  
H Nmr ◽  
35Cl Nqr ◽  
Low Temperature Phase

AbstractThe crystal structure of (CH3)4NTlCl4 and (C2H5)4NTlCl4 was determined at room temperature by single crystal technique. (CH3)4NTlCl4: D2h17-Cmmm; Z = 2; a = 913.2pm, b = 894.6 pm, c = 752.5 pm; (C2H5)4NTlCl4: C6v4-P63mc; Z = 2; a = 827.9 pm, c = 1329.8 pm. (C2H5)4NTlCl4 is isomorphous with (C2H5)4NInCl4. The compounds undergoe a phase transition at 239 K and 222 K, respectively. For both compounds no35 Cl NQR signal was observable in the high temperature phase I due to the dynamics of the anion. The 35 Cl NQR was studied in the low temperature phase II of both compounds as a function of temperature. (CH3)4NTlCl4 shows a two line, (C2H5)4NTlCl4 a four line spectrum. The possible phase II structures and the dynamics of the cation, studied by 1H-NMR, are discussed

A tetranuclear copper (II) complex with pyrazole-3,5-dicarboxylate ligands: synthesis, characterization and electrochemical properties

2016 ◽  
Vol 71 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Selçuk Demir ◽  
Hamide Merve Çepni ◽  
Małgorzata Hołyńska ◽  
Muammer Kavanoz
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Metal Oxidation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complex Anions

AbstractA tetranuclear copper (II) complex with pyrazole-3,5-dicarboxylate ligands (pdc3−), [Me2NH2]4[Cu4(pdc)4], was synthesized using solvothermal and metal oxidation routes and characterized by elemental analysis, infrared, thermogravimetry/differential thermal analysis, and room-temperature magnetic measurements. The structure of the complex was determined by single-crystal X-ray diffraction. It comprises dimethylammonium cations and complex anions containing four Cu2+ cations. The crystal structure is stabilized by N–H···O hydrogen bonds. In addition, the electrochemical behavior was studied.

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