Naslov
Tautomerization of 1-tosylcytosine promoted by metal complexation

Autori
Višnjevac, Aleksandar ; Luić, Marija ; Žinić, Biserka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XVI Croatian-Slovenian crystallographic meeting - Book of abstracts / Popović, Stanko - Zagreb : HKZ, 2007

Skup
XVI Croatian-Slovenian crystallographic meeting

Mjesto i datum
Petrčane, Hrvatska, 13.06.2007. - 17.06.2007

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
tosylcytosine; tautomerisation; metal complexation

Sažetak
Synthetic pathway as well as the molecular and crystal structure of bis[ -(1-(p-toluenesulfonyl)cytosine-N3, N4]-dichloro-bis(dimethylsulfoxide-S)-di-palladium (II) (1) is presented, and compared with structures of dichloro-bis[1-(p-toluenesulfonyl)cytosine-N, O]cadmium (II) (2) and dichloro-bis-[1-(p-toluenesulfonyl) cytosine-N, O]copper (II) (3). It is well documented that cytosine derivatives reveal imino-amino tautomerization (Fig. 1), easily detectable by X-ray diffraction studies by observing of relevant bond distances. We studied herein the imino-amino tautomerization of 1-tosylcytosine promoted by metal coordination. While coordination of cadmium did not provoke any tautomeric change, the copper coordination resulted with unprecedented imino-amino mixed copper(II)complex. It seems that palladium coordination gave first a classical mononuclear complex which underwent chemical conversion when exposed to DMSO, giving a binuclear species 3 with both ligand molecules tautomerically changed (Fig. 2). The positive charge of the central Pd atom is balanced by one chlorine and an N3 from the cytosine ring, which, due the tautomerization bears a negative charge. Additionally, Pd atom is coordinated by the sulphur atom from DMSO and the imine nitrogen. Four donor atoms form a slightly distorted square planar coordination. Interatomic distances between two Pd atoms is in accordance with the values obtained for related structures extracted from CSD. The attempts to synthesize and crystallize the analogous Zn(II), Ni(II) and Co(II) complexes have been unsuccessful so far.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA