Etude de la conformation des n-aryl azoles par la methode e.h.t. (extended hückel theory)

19F,31P,1H NMR and X-ray crystallographic studies of (pentafluorophenyl)3−n (4-pyrazol-1-yl-2,3,5,6-tetrafluorophenyl) n=1,2,3 Phosphines

“…This value is about 26 ~ in N-phenylpyrazole [14]; consequently the interactions present when two H atoms are at ortho position (one attractive, N lone pair/CH, and one repulsive CH/CH) probably become both repulsive (N lone pair/CF and CH/CF).…”

The Structure ofN‐phenyl‐pyrazoles and Indazoles: Mononitro, Dinitro, and Trinitro Derivatives

“…We have published 40 papers on the title topic between 1959 and 2013; this set continues to be the only systematic study of these compounds . Our publications deal with most of these structures: 1 ; 3 ; 4 ; 5 ; 7 ; 9 ; 10 ; 11 ; 13 ; 14 ; and 15 . We have not studied compounds related to structures 2 (3‐nitro), 6 (3,5‐dinitro), 8 (2‐nitro), and 12 (2‐nitro).…”

“…We have published 40 papers on the title topic between 1959 and 2013; this set continues to be the only systematic study of these compounds . Our publications deal with most of these structures: 1 [29,31,35,36,38,44]; 3 [7,8,11,13,14,16,19,22,25,28,29,33,35,37,[39][40][41]43]; 4 [1][2][3][4][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]22,25,26,28,30,31,35,36,…”

N,N-Linked biazoles. III. MNDO calculations on the conformation of N,N-linked biazoles and their quaternary salts

“…The effect of quaternization (compounds [11][12][13][14] in bond angles and distances, although small in absolute terms, causes enough distortion to the whole N-methylated ring as to make significant the variation of internuclear distances between the hydrogen atoms situated "ortho" to the N-N bonded nitrogen in each of the rings with respect to the same atoms on the neighbouring ring in the planar conformations. For example, in the monocation 13 (0 = O")., the distance between the two hydrogen atoms situated more distant to the methyl groups Can observed in the distance between the hydrogen atoms situated at the same side of the methyl groups (labelled as 14 and IS), 2 .…”

“…These studies, both experimental and theoretical, have been extended to heterocyclic derivatives, like phenylpyridines and bipyridines (6-l l ) . However, the case of a single bond of the N, 2-C, z type connecting two aromatic rings (N-phenylazoles) has received much less attention, and only two theoretical studies have been published: one by Cialasso and Alti (12) on N-phenylpyrrole, and another by Avignon, Bouscasse, and Elguero (13) on eight N-arylazoles. The E.H.T.…”