Structural Chemistry, ( ISI ), Volume (22), No (1), Year (2011-1) , Pages (201-210)

Title : ( Different orientations of C=O versus P=O in P(O)NHC(O) skeleton: the first study on an aliphatic diazaphosphorinane with a gauche orientation )

Authors: Atekeh Tarahhomi , Mehrdad Pourayoubi , Arnold L. Rheingold , James A. Golen ,

Access to full-text not allowed by authors

Citation: BibTeX | EndNote

Abstract

Different orientations of P(O) versus C(O) in P(O)NHC(O) skeleton have been discussed in two new phosphorus(V)-nitrogen compounds with formula XP(O)Y and XP(O)Z2 where X = NHC(O)C6H4(4-F) and Y = NHCH2C(CH3)2CH2NH (1), Z = NHC6H4(4-CH3) (2). Compound 1 is the first example of an aliphatic diazaphosphorinane with a gauche orientation which has been studied by X-ray crystallography; the P=O bond is in the equatorial position of the ring. Both compounds show nJ(F,C) and mJ(F,H) coupling constants (n = 1, 2, 3 and 4; m = 3 and 4) and 3J(P,C)[2J(P,C). Quantum chemical calculations were performed with HF and Density Functional Theory (DFT) methods using 6-31?G(d,p) basis set. A tentative assignment of the observed vibrational bands for these molecules is discussed. Compound 1 shows a deshielded C atom of the carbonyl moiety (in 13C NMR spectrum) relative to that of 2, which is supported by IR spectroscopy in which the considerably lower C=O frequency is observed for 1. Comparing the X-ray crystallography and IR spectra of 1 and 2 shows that the acyclic compound 2, containing P=O and C=O bonds in an anti position, are involving in a stronger N–H...O=P hydrogen bond in crystal network. This leads to a weaker P=O and NC(O)NHP(O)–H bonds and stronger N...O interaction. The Namide–H is involved in an intramolecular N–H...O hydrogen bond.

Keywords

, Phosphoric triamides . NMR . X, ray crystallography . Hydrogen bonds . Chemical calculation
برای دانلود از شناسه و رمز عبور پرتال پویا استفاده کنید.

@article{paperid:1020713,
author = {Tarahhomi, Atekeh and Pourayoubi, Mehrdad and Arnold L. Rheingold and James A. Golen},
title = {Different orientations of C=O versus P=O in P(O)NHC(O) skeleton: the first study on an aliphatic diazaphosphorinane with a gauche orientation},
journal = {Structural Chemistry},
year = {2011},
volume = {22},
number = {1},
month = {January},
issn = {1040-0400},
pages = {201--210},
numpages = {9},
keywords = {Phosphoric triamides . NMR . X-ray crystallography . Hydrogen bonds . Chemical calculation},
}

[Download]

%0 Journal Article
%T Different orientations of C=O versus P=O in P(O)NHC(O) skeleton: the first study on an aliphatic diazaphosphorinane with a gauche orientation
%A Tarahhomi, Atekeh
%A Pourayoubi, Mehrdad
%A Arnold L. Rheingold
%A James A. Golen
%J Structural Chemistry
%@ 1040-0400
%D 2011

[Download]