Search results for "bond"

Analysis of the main structural trends for biscyclometalated dinuclear rhodium compounds of general formula Rh2(O2CR)2(PC)2·2H2O

2008

Abstract A new series of biscyclometalated dinuclear rhodium (II) compounds with the general formula Rh2(O2CR)2(PC)2 · 2H2O, being PC = (C6H4)P(C6H5)2, R = CH3 (1 · 2H2O), PC = [(p-CH3 OC6H3)P(p-CH3 OC6H4)2], R = CF3 (2 · 2H2O), PC = (C6H4)P[CH(CH3)2]2, R = CH3 (3 · 2H2O) and PC = (C6H4)P(C6H5)2, R = C6F5 (4 · 2H2O) has been obtained. The crystal structures for these compounds have been determined by X-ray diffraction and the main structural trends, bond lengths, bond angles and torsion angles have been analyzed, and have also been compared with the structural parameters for different analogous complexes described previously in the literature.

Structures and Magnetic Properties of Bis(μ‐phenoxido), Bis(μ‐phenoxido)‐μ‐carboxylato and Bis(μ‐phenoxido)bis(μ‐carboxylato) Fe III Ni II Compounds …

2015

This report describes the syntheses, characterization, crystal structures and magnetic properties of five dinuclear FeIIINiII compounds derived from two Robson-type tetraiminodiphenol macrocyclic ligands H2L1 and H2L2, which are the [2+2] condensation products of 4-ethyl-2,6-diformylphenol and 1,3-diaminopropane (for H2L1) or 2,2-dimethyl-1,3-diaminopropane (for H2L2). The compositions of the compounds are [FeIII(N3)2L1NiII(H2O)2](ClO4) (1), [FeIII(benzoato)L1NiII(H2O)(μ1,3-benzoato)](ClO4) (2), [FeIII(benzoato)L2NiII(H2O)(μ1,3-benzoato)](ClO4) (3), [FeIIIL2NiII(μ1,3-acetato)2](ClO4)·H2O (4) and [FeIIIL2NiII(μ1,3-propionato)2](ClO4)·H2O (5). The bridging moieties between the two metal ions …

Über gemischte bindungen in der IV. Hauptgruppe

1984

Abstract The reaction of Ph 3 PbLi with Ph 3 SnCl or Ph 3 GeCl gives Ph 3 PbSnPh 3 and Ph 2 PbGePh 3 , respectively; there is no reaction with Ph 3 SiCl. Ph 3 SiLi reacts with Ph 3 PbCl to form a regular 1 : 1 Pb 2 Ph 6 · Si 2 Ph 6 phase. The compounds have been investigated by mass, NMR and vibrational spectra: 207 Pb NMR chemical shifts with respect to PbMe 2 −79.8 (Pb 2 Ph 6 ), −256.5 (Ph 3 PbSnPh 3 ), −271.5 ppm (Ph 3 PbGePh 3 ); stretching vibrations 112 (PbPb), 125 (PbSn), 138 cm −1 (PbGe). The crystal structures have been determined and refined to R = 0.061 (Ph 3 PbSnPh 3 , −40°C), 0.053 (Ph 3 PbGePh 3 , −50°C), 0.068 (Pb 2 Ph 6 · Si 2 Ph 6 , 20°C); bond lengths 285 (PbPb),…

Über Arsen‐haltige Heterocyclen, I. Molekül‐ und Kristallstruktur von 2‐Chlor‐1,3,6,2‐trithiarsaocan

1974

Die Struktur der Titelsubstanz (2) wurde rontgenographisch aus Diffraktometer-Einkristalldaten bestimmt und bis zu einem konventionellen R von 0.037 verfeinert. Der 8-Ring hat eine deformierte Wannenform mit transannularer 1,5-AsS-Annaherung. 2 ist dissymmetrisch, der wechselseitige Ubergang zwischen den beiden Spiegelbildisomeren wird besprochen. Die Koordination am As-Atom ist ψ-trigonal-bipyramidal mit axialen Abstanden AsCl 2.36 A, AsS 2.72 A und aquatorialen Abstanden AsS 2.25 und 2.26 A. Bekannte AsS-Abstande und Koordinationen werden diskutiert und Standardwerte fur AsS- und SbS-Abstande verschiedenen Bindungstyps ermittelt. 2 bildet ein Modell fur die Blockierung von Enzym-Proteinen…

Über Phosphor‐haltige Heterocyclen, II: Molekül‐ und Kristallstruktur von 1,2,3,4,5‐Pentaphenyl‐1λ 5 ‐phosphol‐1‐on

1976

Die Struktur der Titelsubstanz wurde rontgenographisch aus Diffraktometer-Einkristalldaten bestimmt und bis zu einem konventionellen R von 0.076 verfeinert. Der 5-ring besitzt „envelope”-Konformation. Fehlende Planaritat und Bindungslangenverteilung schliesen eine Elektronendelokalisation im λ5-Phospholsystem aus. Das Propellersystem der Phenylsubstituenten bildet eine Cs-symmetrische Doppelschneckenschraube. Die Struktur besteht aus 14-fach koordinierten Molekulen. On Heterocyclic Systems Containing Phosphorus, II: Molecular and Crystal Structure of 1,2,3,4,5-Pentaphenyl-1 λ5-phosphol-1-one The crystal structure of the title compound has been determined from single crystal X-ray data and r…

The Pd3(dppm)3(CO)n clusters (n = 1-,2-); rare cases of anionic palladium species.

2010

Two novel anionic palladium clusters, Pd(3)(dppm)(3)(CO)(n-) (Pd(3)(n); n = 1-,2-) were electrochemically generated from the dicationic cluster Pd(3)(2+) in 0.2 M THF/Bu(4)NPF(6)via two first consecutive reversible 1-electron reductions (Pd(3)(2+) + 1 e(-) ⇌ Pd(3)(+), -0.210, and Pd(3)(+) + 1 e(-) ⇌ Pd(3)(0), -0.470 V vs. SCE) followed by two others at -2.350 (Pd(3)(0) + 1 e(-) ⇌ Pd(3)(1-), reversible) and at -2.690 V vs. SCE (Pd(3)(1-) + 1 e(-) ⇌ Pd(3)(2-), irreversible). The chemical stability and instability, respectively, of the Pd(3)(dppm)(3)(CO)(n-) clusters (Pd(3)(n); n = 1-,2-) at the time scale of the electrochemical experiments were addressed by DFT computations. Indeed, geometry …

Unexpected C–C bond formation with a ferrocenyl Fischer carbene complex

2020

Dependence of the energy of water molecules in clusters upon hydrogen bonds: a Hirshfeld study

2008

Abstract: The energy of water clusters, containing up to 20 water molecules, are partitioned into molecular contributions using the Hirshfeld method at the DFT level. The molecular energies are analyzed with respect to the hydrogen bonding network in the clusters.

Spin‐Crossover 2D Metal–Organic Frameworks with a Redox‐Active Ligand: [Fe(ttf‐adpy) 2 M(CN) 4 ]· n H 2 O (ttf‐adpy = 4‐Tetrathiafulvalenylcarboxamid…

2008

A new ttf (tetrathiofulvalene) ligand containing an amidopyridine moiety was synthesized and characterized. The electrochemical study of the 4-tetrathiofulvalenylcarboxamidopyridine (ttf–adpy) ligand showed two reversible oxidation processes at EI′1/2 = 0.08 V/Fc+–Fc and EII′1/2 = 0.26 V/Fc+–Fc. The crystal structure of [(ttf–adpyH)2Pt(CN)4] (1) was solved at 293 K, where 1 displays the triclinic space group P. The ttf–adpyH+ molecule is planar, and the bond lengths within the ttf core are in the usual range for neutral ttf moieties. The ttf–adpyH+ molecules and the [Pt(CN)4]2– anions organize in a three-dimensional network by means of hydrogen bonds and short S···S contacts. In the network…

N-methyl-1,2-dihydro-2-benzoylmethylenequinolines: configurational dissimilarity with unmethylated congeners

2000

Abstract Twelve 1-methyl-1,2-dihydro-2-benzoylmethylenequinolines have been synthesized and their structures elucidated by 1 H, 13 C and 15 N NMR, UV–Vis and X-ray methods. The results unambiguously show that these compounds and the corresponding 1,2-dihydro-2-benzoylmethylenequinolines both in crystalline and in solution state are the Z and E isomers, respectively. Comparison of the X-ray structures reveal that ( Z )-1,2-dihydro-2-benzoyl-methylenequinolines are less twisted as compared to their 1-methyl derivatives. This difference is caused by formation of the quasi-aromatic six-membered ring stabilized by an intramolecular hydrogen bond in unmethylated congeners, prevented by N -methyla…