Pressure-tuning infrared and solution Raman spectroscopic studies of 17β-estradiol and several A-ring and 17α-ethynylestradiol derivatives

Study of IR spectrum of the 17β-estradiol using quantum-chemical density functional theory

“…The scaling factors used for the frequencies corrections of stretching () vibrations are equal to 0.95 (for the C-H and O-H bonds), to 0.965 (for the C-C bonds in aromatic ring), and to 0.97 (for deformation vibrations). Comparing the calculated forms of normal vibrations with those assignments of the bands in IR spectrum of estradiol described in the literature [3], we were able to appreciate the possibilities of the calculation method used in order to predict the frequencies and forms of vibrations as well as the intensity of absorption band in the IR spectra of steroid hormones; to reveal the adjustment value for anharmonicity of vibrations and correlation of electrons (scaling factor) as well as to perform the assignment of those experimental IR bands of estradiol [3,5], the vibrational modes of which are not described in the literature.…”

“…Reasoning from the fact that the absorption in phenols at the presence of hydrogen bonds of the O-H…O type takes place at smaller energies (3250-3200 cm -1 ), than in the secondary alcohols (3300 cm -1 ), broad band of absorption at 3446 cm -1 was related by authors of Ref. [3] to stretching vibrations of O-H bond of cyclopentanol ring, and at 3240 cm -1 was related to stretching vibrations of O-H bonds of the phenol ring. By comparison of the calculated and experimental data we have supposed that in the solid samples of estradiol the O-H groups of phenol and cyclopentanol rings form intermolecular hydrogen bonds with different energies and therefore the different displacement of n(OH) bands takes place towards the lower frequencies and the rearrangements of vibration modes occurs.…”

“…In Ref. [3] the absorption band in estradiol IR spectrum at 1283 cm -1 (in the Raman spectrum at 1287 cm -1 (in dimethylphormamide) and at 1289 cm -1 (in acetone)) was considered to be d(OH) vibration in the cyclopentanol ring. Our calculations have shown that the vibration mode number 79 with the calculated frequency of 1299 cm -1 belongs to deformational vibrations of the OH-group at the carbon atom C 17 , mixing up with the skeletal vibrations of C-C bonds of the C and D rings as well as deformation vibrations of the CH 2 -and CH-groups of these rings.…”

Crystallization of ?-estradiol in an acrylic transdermal drug delivery system

“…The peak assignments for estradiol are discussed at length by Butler et al 17 The Raman spectra of EH and AE are shown in Figure 6. The distinguishing features between the spectra of crystalline and amorphous estradiol are in the lower wave number region.…”

Solid State and Thermal Behavior of 17β-Estradiol in Ammonioethyl Methacrylate Ester Copolymer

“…E 2 -hemihydrate exhibited very broad bands centered at 3435.95 and 3232.06 cm -1 attributed to O-H stretching of hydroxyl group adjacent to C-17 and C-3 positions in E 2 chemical structure, respectively (Barnett 1995;Wiranidchapong 2006;Wiranidchapong 2008;Wiranidchapong 2009). The broad band characteristic indicates the hydrogen-bonded hydroxyl group with water entrapped in the crystal structure.…”