Syntheses of THF solutions of SeX2 (X = Cl, Br) and a new route to selenium sulfides SenS8-n (n=1-5): X-ray crystal structures of SeCl2(tht)(2) and SeCl2 center dot tmtu
A. Maaninen et al., Syntheses of THF solutions of SeX2 (X = Cl, Br) and a new route to selenium sulfides SenS8-n (n=1-5): X-ray crystal structures of SeCl2(tht)(2) and SeCl2 center dot tmtu, INORG CHEM, 38(18), 1999, pp. 4093-4097
A simple and efficient synthesis of solutions of pure SeCl2 in THF or dioxa
ne (ca. 0.4 M) at 23 degrees C was achieved by treatment of elemental selen
ium with an equimolar amount of SO2Cl2. SeCl2 was characterized by Se-77 NM
R and Raman spectra. SeCl2 forms 1:1 or 1:2 adducts with tetramethylthioure
a (tmtu) or tetrahydrothiophene(tht), respectively. The crystal structure o
f SeCl2 tmtu (1) reveals a T-shaped geometry [d(Se-Cl) = 2.443(4) Angstrom]
with weak intramolecular Se ... Cl interactions [d(Se-Cl) = 3.276(4) Angst
rom]. Crystals of 1 are triclinic, space group P (1) over bar, with a = 8.4
73(3) Angstrom, b = 9.236(3) Angstrom, c = 7.709(4) Angstrom, alpha = 109.9
0(3)degrees, beta = 92.26(4)degrees, gamma = 107.89(3)degrees, V = 532.9(4)
Angstrom(3), and Z = 2. The complex SeCl2(tht)(2) (2) adopts a square plan
ar geometry with d(Se-Cl) = 2.4149(8) Angstrom. Crystals of 2 are monoclini
c, space group C2/c, with a 15.6784(8) Angstrom, b = 9.1678(4) Angstrom, c
= 9.1246(4) Angstrom, beta = 110.892(2)degrees, V = 1225.3(1) Angstrom,(3)
and Z = 4. The reaction of Ph3PS with SeCl2 gives Ph3PCl2 and a complex mix
ture of selenium sulfides SenS8-n, (n = 1-5), which were identified by 77Se
NMR. Halogen exchange between SeCl2 and Me3SiBr in THF yields thermally un
stable SeBr2 (ca. 0.4 M) characterized by Se-77 NMR and Raman spectra.