Open AccessDETERMINATION OF PENTAACETYLSARMENTOSIN CRYSTAL STRUCTURE
Author(s) -
Gu Yuan-Xin,
Zheng Chao-De,
Qian Jin-Zi,
QiTai Zheng
Publication year - 1981
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.30.393
Subject(s) - diffractometer , crystal structure , molecule , physics , crystal (programming language) , reflection (computer programming) , matrix (chemical analysis) , derivative (finance) , crystallography , materials science , combinatorics , optics , mathematics , chemistry , computer science , quantum mechanics , programming language , financial economics , economics , composite material
Pentaacetylsarmentosin is a derivative of Sarmentosin which is one of effective component of plant Sedum sarmentosum Bunge. The molecular formula is C21H27O12N. Pentaacetylsarmentosin crystals belongs to the orthogonal system, space group D24P212121. The cell dimensions are a = 19.756(3)?, 6 = 17.013(3)?, c = 7.482(1)?; four molecules are contained in a cell (z = 4). Intensity data were collected on a PW-1100 four circle diffractometer.The original MULTAN-78 was not successful in solving the structure, the correct structure solution was obtained by optimal selection method used to improve the index distribution of starting reflection set.Refinement of the structure paramenters was acheived by block-matrix Least-squares (program XTL (1974)), R = 0.051 (sin θ/λ≤ 0.48), R = 0.063 (all observed reflections). All the positions of hydrogen atoms except the methyes were located by the difference syntheses.