نتایج جستجو برای: alternative substituents

تعداد نتایج: 311992  

2011
Oliver Brücher Uwe Bergsträsser Harald Kelm Jens Hartung

The title compound, C(10)H(19)NO(3), is a disubstituted piperidine bearing substituents in two equatorial positions. One of the substituents is a hy-droxy group bound to nitro-gen and the second a tert-butyl ester group bound to the carbon next to the endocyclic nitro-gen. Enanti-omers of the title compound form hydrogen-bridged dimers across a center of inversion.

1987
H. HAYD H. SAVIN

Pseudopotential SCF calculations for YaC-X, Y =H, F; X=H, F, CI, PH2, PF2 and a simple model, simulating the substituents by a homogeneous, electric field, are presented in order to rationalize the substitution effect on the C-X bond.

Journal: :Dalton transactions 2006
Dawn M Friesen Owen J Bowles Robert McDonald Lisa Rosenberg

The synthesis and structural characterization of a series of tripodal tris(phosphine) ligands, containing SiMe2 elbow groups, is described. The significant steric congestion in these ligands, due to the silylmethyl substituents, is manifest both in the solid-state structures and in the solution NMR spectra of the free ligands. Variable temperature 1H{31P} NMR studies of one of the ligands, CH3C...

2017
Jim Simpson Shaaban K Mohamed Adel A Marzouk Antar A Abdelhamid Mustafa R Albayati

The title compound, C24H21N3O3, crystallizes with two unique but closely r.m.s. overlay fit = 0.215 Å) comparable mol-ecules (1 and 2) in the asymmetric unit of the triclinic unit cell. In molecule 1, the dihedral angles between the central imidazlole ring and the benzene-ring substituents are 42.51 (9), 45.41 (9) and 56.92 (8)°, respectively. Comparable data for molecule 2 are 39.36 (10), 34.4...

2016
Véréna Poinsot Matthew B. Crook Stéphanie Erdn Fabienne Maillet Adeline Bascaules Jean-Michel Ané

Soil-dwelling, nitrogen-fixing rhizobia signal their presence to legume hosts by secreting lipo-chitooligomers (LCOs) that are decorated with a variety of chemical substituents. It has long been assumed, but never empirically shown, that the LCO backbone is synthesized first by NodC, NodB, and NodA, followed by addition of one or more substituents by other Nod proteins. By analyzing a collectio...

2011
Thomas Huhn Ulrich Groth Calin Deleanu

Keywords: Pyrrolodiazine Fluorescence Blue luminophores Microwave Cyc\oadditions A fast, efficient, general and environmentally friendly method for preparation of highly fluorescent derivatives containing the pyrrolodiazine moiety using microwave (MW) irradiation, in liquid phase, is reported. Under MW irradiation the yields are much higher, sometimes substantially (by almost double) and, the a...

Journal: :Dalton transactions 2015
Tatiana V Dubinina Anton D Kosov Elizaveta F Petrusevich Sergey S Maklakov Nataliya E Borisova Larisa G Tomilova Nikolay S Zefirov

Novel heteroleptic naphthalo-phthalocyaninates of lutetium possessing a symmetrical substituted naphthalocyanine deck were synthesized on the basis of two preformed synthetic blocks: naphthalocyanine ligand and lutetium phthalocyaninates. The compounds obtained were characterized by (1)H NMR and high-resolution MALDI-TOF/TOF mass spectrometry. The correlation between the nature of the substitue...

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