Naslov
Crystal structure of tripotassium trisaccharinate dihydrate, K_3(C_7H_4NO_3S)3 ^. 2 H_2O

Autori
Kaitner, Branko ; Jovanovski, Gligor ; Grupče, Orhideja ; Naumov, Panče

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

Izvornik
9th Slovenian-Croatian Crystallographic Meeting, Book of Abstracts and Programme / Leban, Ivan ; Lah, Nina - Ljubljana : Univerza v Ljubljani, 2000

Skup
9th Slovenian-Croatian Crystallographic Meeting

Mjesto i datum
Gozd Martuljek, Slovenija, 15.06.2000. - 17.06.2000

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
metal saccharinates; X-ray crystal structure determination

Sažetak
Crystal data: C_21H_12N_3O_9S_3K_3^.2H_2O, M_r = 1399.70, triclinic, space group P-1, a = 7.6191(5), b = 12.3552(7), c = 15.5209(12) A, a = 72.293(7), b = 86.581(6), c = 81.265(5) ^o, V = 1372.23 A^3, D_x = 1.694 gcm^-^3, Z = 2. Three-dimensional data [4299 independent reflections with intensity greater than 2s(I)] were collected on four-circle Philips PW 1100 single crystal diffractometer using MoK_a radiation. The structure was refined to R = 0.040. Similarly to the previously studied trisodium trisaccharinate dihydrate the structure of the studied potassium compound consists of three crystallo-graphically independent potassium and saccharinato ions as well as two structurally different water molecules. Two of the K^+ cations are six-coordinated (K1 is surrounded by five saccharinato oxygens and one water oxygen atom, whereas K3 has, as nearest neighbours, four saccharinato oxygens, one saccharinato nitrogen atom and one water oxygen atom). The third K^+ cation (K2) is seven-coordinated, being surrounded by five saccharinato oxygens and two water oxygen atoms. All polyhedra are irregular. The K-O distances range from 2.655(3) to 3.097 A (mean 2.790 A) whereas the K-N distance is 3.022 A. The shorter mean K-O distance (2.790 A) in the studied compound compared to the found mean K-O value (2.818 A) in dipotassium sodium trisaccharinate monohydrate suggests stronger interaction between the K^+ cations and saccharinato anions in the former compound. There are no significant differences between the interatomic distances and angles in the crystallographically different saccharinato anions. The carbonyl and sulfonyl saccharinato oxygen atoms as well as the saccharinato nitrogen atoms are involved in the hydrogen bonds of medium strengths with the water molecules. It is worth mentioning that one of the two crystallographically different water molecules (W2) was found to be disordered, the corresponding occupation factors being approximately 0.6, 0.2 and 0.2.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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