Journal of the Chemical Society. Perkin transactions II p. 1025 - 1030 (1983)
Update date:2022-09-26
Topics:
Desiraju, Gautam R.
The thermal transformation of the low (1a) to the high temperature (1b) form of 2-amino-3-hydroxy-6-phenylazopyridine has been studied by differential scanning calorimetry and variable temperature i.r. spectroscopy.Form (1a) is converted into (1b) through two intermediate phases and the i.r. spectra show changes in the >C=C< and -N=N- sterches.X-Ray crystal structures of (1a and b) have been determined.The red crystals of (1a) are orthorombic, a = 10.026(7), b = 20.452(9), c = 10.111(9) Angstroem; the space group is Pbca and the structure has been refined to R 0.080 for 443 non zero reflections.The blue crystals of (1b) are monoclinic, a = 22.666(6), b = 3.886(4), c = 11.373(7) Angstroem, β = 91.82(3) deg; the space group is P21/c and the structure has been refined to R 0.048 for 607 non-zero reflections.The bond lengths in (1a and b) are in accord with a hydroxazo and a quinone hydrazone structure, respectively.The hydrogen bonding in each form can only be explained if (1a) is the azo and (1b) the hydrazone tautomer.In the crystal stucture of (1a), the hydroxy-group is close to an azo-group of an adjacent molecule and the solid state tautomerization can be accounted for by an intermolecular co-operative shift of protons across the various hydrogen bonds in structure (1a).
View MoreTaizhou Chemedir Biopharm-tech Co., Ltd
Contact:+86 523 86200218
Address:G09, No. 1 Avenue China Medical City, Taizhou,Jiangsu, China
PharmaResources(Kaiyuan)CO,.Ltd
Contact:+86-21-50720028
Address:No.3, Beihuan Road, Economic Development District, Kaiyuan City, Tieling City, Liaoning Province, China 112300
Chengdu Chengnuo New-Tech Co., Ltd
Contact:0086-028-85749078
Address:4 Jiuyang road,Jiulong industrial port,Chengdu, China
website:http://www.greenutra.cn
Contact:0086-411-39553357
Address:No. 7-1-1802, Huizhi Garden,Ocean Square,Dalian, 116033, China
website:http://www.win-winchemical.com
Contact:0086-577-64498589
Address:6F, No. 396 Xingping Road, Longwan Industrial Zone, Wenzhou City, Zhejiang, 325000 P.R.China
Doi:10.1007/BF00765719
(1981)Doi:10.1021/ja210587q
(2012)Doi:10.1246/cl.1981.457
(1981)Doi:10.1016/j.bmcl.2005.07.052
(2005)Doi:10.1016/S0960-894X(02)01040-5
(2003)Doi:10.1016/j.tet.2004.08.003
(2004)
