Abstract:C2oH24NO5P, Mr=389"40, monoclinic, P2~/a, a = 15.332 (3), b = 10-603 (6), 3 c= 12.442 (6) ,h,, fl = 100.89 (3) °, V = 1986 (1) A, Z = 4, Dx=l.30gcm -3, MoKa, A=0"7107A, /z = 1.84cm -~, F(000)= 824, room temperature, R= 0.059 for 2108 observed reflections [Fo > 3or(Fo)]. Out of l l C---C bonds of the biphenyl ring, four bonds (1-35-1-38 A) are significantly shorter than the others * Present address: (1-40-1.43 A). Two P--O single bonds are 1.564 (4) and 1-560 (4)/~ in length, and the P--O double-bond length is … Show more
“…The mean PÐ O single-bond distance of 1.565 (3) A Ê for (I) and (II) is in agreement with the reported value of 1.564 (5) A Ê for the structure of diethyl (1-hydroxy-2-butynyl)phosphonate (Sanders et al, 1996). The P1 O1 double-bond distances in (I) and (II) are comparable with the reported values of 1.464 (2), 1.459 (3) and 1.454 (4) A Ê [Naidu et al (1992), Boehlow et al (1997) and Yokota et al (1990), respectively]. The P1ÐC15 single-bond lengths in both compounds are in good agreement with reported values of 1.791 (2) and 1.806 (6) A Ê (Weichsel & Lis, 1996;Liu et al, 1995;Perales & Garcõ Âa-Blanco, 1977;Howells et al, 1973).…”
The title compounds, C(27)H(26)Cl(2)NO(5)PS, (I), and C(27)H(27)BrNO(5)PS, (II), respectively, crystallize in the centrosymmetric space group P2(1)/n with one molecule in the asymmetric unit in each case. The dihedral angle between the benzene and pyrrole rings is 2.1 (1) degrees in (I) and 0.9 (2) degrees in (II). The phenylsulfonyl group is orthogonal to the halophenyl moiety, with a dihedral angle of 82.0 (1) degrees in (I) and 78.7 (2) degrees in (II). In both compounds, the molecular structures and packing are stabilized by C-H...O and C-H...halogen interactions. The intermolecular hydrogen bonds in (I) form cyclic dimers with graph-set descriptors R(2)(1)(10) and R(2)(2)(8) about a 2(1) axis, and those in (II) form a C(2)(2)(20) chain.
“…The mean PÐ O single-bond distance of 1.565 (3) A Ê for (I) and (II) is in agreement with the reported value of 1.564 (5) A Ê for the structure of diethyl (1-hydroxy-2-butynyl)phosphonate (Sanders et al, 1996). The P1 O1 double-bond distances in (I) and (II) are comparable with the reported values of 1.464 (2), 1.459 (3) and 1.454 (4) A Ê [Naidu et al (1992), Boehlow et al (1997) and Yokota et al (1990), respectively]. The P1ÐC15 single-bond lengths in both compounds are in good agreement with reported values of 1.791 (2) and 1.806 (6) A Ê (Weichsel & Lis, 1996;Liu et al, 1995;Perales & Garcõ Âa-Blanco, 1977;Howells et al, 1973).…”
The title compounds, C(27)H(26)Cl(2)NO(5)PS, (I), and C(27)H(27)BrNO(5)PS, (II), respectively, crystallize in the centrosymmetric space group P2(1)/n with one molecule in the asymmetric unit in each case. The dihedral angle between the benzene and pyrrole rings is 2.1 (1) degrees in (I) and 0.9 (2) degrees in (II). The phenylsulfonyl group is orthogonal to the halophenyl moiety, with a dihedral angle of 82.0 (1) degrees in (I) and 78.7 (2) degrees in (II). In both compounds, the molecular structures and packing are stabilized by C-H...O and C-H...halogen interactions. The intermolecular hydrogen bonds in (I) form cyclic dimers with graph-set descriptors R(2)(1)(10) and R(2)(2)(8) about a 2(1) axis, and those in (II) form a C(2)(2)(20) chain.
“…This was the first example of a six-membered ring formationvia carbonyl oxygen coordination. Earlier work − was concentrated on the formation of phosphorus compounds containing four- and five-membered cyclic systems showing oxygen coordination. …”
A series of phosphorus compounds 1-5 containing carbonyl or carboxyl groups was obtained and subjected to X-ray analysis. Syntheses of the phosphoranes 1 and 5 were effected by oxidation reactions using potassium permaganate, while the phosphine oxide 2 was obtained by oxidation with hydrogen peroxide. The readily available phosphines 3 and 4 were included in the study. The structures revealed that P-O coordination occurred for 1-3 in the presence of extensive hydrogen bonding and led to trigonal bipyramidal geometries. A similar structure was observed for 4 in the absence of hydrogen bonding. (31)P chemical shifts indicate retention of the basic coordination geometries in solution. Consideration of the chirality of the phosphoranes 1 and 5 leads to a pair of mirror images that are possible in solution but exist in preferred isomeric forms in the crystalline state. Evaluation of the energies of two competing bonding types indicated a range for P-O coordination above and below the hydrogen bond energy. The results suggest that phosphoryl transfer enzyme mechanisms should benefit by taking into account donor interactions to phosphorus by residues at active sites in addition to the inclusion of hydrogen bonding interactions.
“…Recent literature on carbonyl donor action has demonstrated the formation of four- 19-21 and five-membered 22-24 ring systems. With the inclusion of OR groups, a wider variety of donor−acceptor interactions is known giving similar size rings. ,− Some examples are shown in Chart , which includes three examples − with potential for donor−acceptor interactions but whose X-ray structures give excessively long P−O distances. Of the ones that form small-membered ring systems, they are by necessity rigid compared to that for the conformationally more flexible six-membered cyclic systems employed in the present study.…”
Section: Introductionmentioning
confidence: 99%
“…S0020 With the inclusion of OR groups, a wider variety of donoracceptor interactions is known giving similar size rings. 21,[25][26][27][28][29][30] Some examples are shown in Chart 2, which includes three examples [31][32][33] with potential for donor-acceptor interactions but whose X-ray structures give excessively long P-O distances.…”
The new cyclic compound 2,2'-sulfurylbis(4-methyl-6-tert-butylphenyl) methyl 2-benzoate phosphite, O(2)S[(t-Bu)MeC(6)H(4)O](2)(OC(6)H(4)CO(2)Me)P (3), containing a salicylate ligand was synthesized from 2,2'-sulfurylbis(4-methyl-6-tert-butylphenyl) chlorophosphite and methyl salicylate in the presence of triethylamine in ether solution. X-ray analyses of bis(methyl salicylate-O)phenylphosphine, (OC(6)H(4)CO(2)Me)(2)PPh (1), and bis(methylsalicylato-O)phenyl(tetrachlorophenylene-1,2-dioxy)phosphorane, (O(2)C(6)Cl(4))(OC(6)H(4)CO(2)Me)(2)PPh (2), as well as that for 3 were obtained. The phosphane 1 has a pseudo trigonal bipyramidal (TBP) structure due to coordination of a carbonyl oxygen atom at an axial site. The cyclic phosphorane 2 and the phosphite 3 lack any coordination from salicylate ligands. This results in a TBP geometry and a pyramidal geometry respectively for 2 and 3. Comparisons with X-ray structures for carboxylate-containing phosphorus compounds exhibiting oxygen coordination show the formation of four- and five-membered cyclic systems. Thus, 1 appears to be the first example of formation of a six-membered ring via carbonyl oxygen coordination. Reference is made to the tyrosyl-tRNA synthetase system where it is proposed that carbonyl oxygen atom coordination is a likely occurrence in the transition state on the basis of the analysis presented in this work.
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