DISSOLUTION OF LANTHANIDE AND ACTINIDE METALS USING IODINE AND 2-PROPANOL - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURES OF LNI(3)(HO-I-PR)(4) (LN=LA, CE) AND TH2I4(O-I-PR)(4)(HO-I-PR)(2)
Dm. Barnhart et al., DISSOLUTION OF LANTHANIDE AND ACTINIDE METALS USING IODINE AND 2-PROPANOL - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURES OF LNI(3)(HO-I-PR)(4) (LN=LA, CE) AND TH2I4(O-I-PR)(4)(HO-I-PR)(2), Inorganic chemistry, 34(19), 1995, pp. 4862-4867
Reaction of lanthanum, cerium, or neodymium metals with 3/2 equiv of i
odine in 2-propanol leads to formation of the alcohol adducts LnI(3)(H
O-i-Pr)(4) (Ln = La (1), Ce (2), Nd (3)) in good yield. Reaction of th
orium metal turnings with 2 equiv of iodine in 2-propanol produces the
dimeric halide-alkoxide complex Th2I4(O-i-Pr)(4)(HO-i-Pr)(2) (4). The
molecular structures of 1, 2, and 4 have been determined by means of
single-crystal X-ray diffraction studies. 1 and 2 are found to be isos
tructural, and consist of seven-coordinate metal centers best describe
d as capped trigonal prisms in which an iodide ligand caps a rectangul
ar face defined by the four 2-propanol oxygen atoms. Ln-I bond lengths
lie in the ranges 3.180(1)-3.224(1) for 1 and 3.157(1)-3.191(1) Angst
rom for 2, while Ln-O distances to the 2-propanol ligands average 2.50
9(7) and 2.488(5) Angstrom for 1 and 2, respectively. 4 exhibits an ed
ge-shared bioctahedral geometry with 2-propoxide ligands occupying bri
dging positions. Bridging Th-O distances in 4 are 2.327(6) and 2.399(6
) Angstrom, while the Th-O distance to the terminal 2-propoxide ligand
is extremely short at 2.056(7) Angstrom. The Th-O bond length to the
2-propanol ligand is characteristically long at 2.437(6) Angstrom, whi
le Th-I distances are 3.094(1) and 3.104(1) Angstrom. Crystal data for
1 (at -70 degrees C): orthorhombic space group Pbca, a = 17.240(3) An
gstrom, b = 13.944(2) Angstrom, c = 19.178(2) Angstrom, V = 4610.3 Ang
strom(3), d(calc) = 2.190 g cm(-3), Z = 8, R = 0.0439, R(w) = 0.0739.
Crystal data for 2 (at -70 degrees C): orthorhombic space group Pbca,
a = 17.199(3) Angstrom, b = 13.884(3) Angstrom, c = 19.153(4) Angstrom
, V = 4573.5 Angstrom(3), d(calc) = 2.211 g cm(-3), Z = 8, R = 0.0352,
R(w) = 0.0619. Crystal data for 4 (at -48 degrees C): triclinic space
group P $($) over bar$$ 1, a = 9.658(2) Angstrom, b = 9.754(2) Angstr
om, c = 11.563(2) Angstrom, alpha = 109.41(3)degrees, beta = 95.18(3)d
egrees, gamma = 117.33(3)degrees, V = 873.5 Angstrom(3), d(calc) = 2.5
21 g cm(-3), Z = 1, R = 0.0319, R(w) = 0.0506.