Study on isomerization of the ligand dibutyl maleate

Citation
Kl. Tang et al., Study on isomerization of the ligand dibutyl maleate, ACT CHIM S, 59(10), 2001, pp. 1628-1632
Citations number
7
Language
CHINESE
art.tipo
Article
Categorie Soggetti
Chemistry
Journal title
ACTA CHIMICA SINICA
ISSN journal
0567-7351 → ACNP
Volume
59
Issue
10
Year of publication
2001
Pages
1628 - 1632
Database
ISI
SICI code
0567-7351(2001)59:10<1628:SOIOTL>2.0.ZU;2-G
Abstract
The tungsten complex W(CO)(4)(phen) (phen = 1,10 - phenanthroline) reacted in toluene refluxing for 24 hours with unpurified dibutyl maleate, which wa s commercially purchased, to give a dark brown solution. The solution was s eparated by column chromatography on silica gel and two main chromatographi c bands were collected. The orange block crystals (1) and the red orange pl atelet crystals (2) were obtained by slow diffusion of petroleum ether into the toluene solutions of the two bands respectively. The crystal structure s are W(CO)(2)(phen)(DBF)(2)(1) and W(CO)(2)(phen)(DBF)(DBM) (2) (DBF = dib utyl fumarate, DBM = dibutyl maleate), determined by the X - ray diffractio n method. In the molecules of both crystals tungsten atom coordination is d istorted octahedral with tire two CO groups and phen in the equatorial plan e and the metal binds in an 2 fashion to C-C bonds of DBM or DBF. Crystal d ata for complex 1: space group R - 3, a = 3.026 4 (4) nm, b = 3.026 4(4) nm , c = 2.135 2(4) nm, alpha = 90 degrees, beta = 90 degrees, gamma = 120 deg rees, V = 16.936(4) nm(3), D, = 1.547 g/cm(3), Z = 18, R = 0.049 1 for 6 62 4 independent reflections. Crystal data for complex 2 : space group P2(1)/n , a = 1.038 2(2) nm, b = 1.428 1(3) nm, c = 2.530 3(5) nm, alpha = 90 degre es, beta = 92.74(3)degrees, gamma = 90 degrees, V = 3.747 (0) nm(3), D-c = 1.554 g/cm(3), Z = 4, R = 0.039 3 for 8 562 independent reflections. The an alysis of the contents for DBM and DBF in the unpurified dibutyl maleate an d the quantitative calculation for the total content of DBF in the two prod ucts indicate that in the coordination reaction the ligand DBM was probably partly isomerized into DBF which is more stable.