Template Synthesis and Reactions of Tricarbonylmolybdenum Phosphadithiamacrocycle Complexes

Treatment of
[Me4N]2[PhP(CH2CH2S)2]
with [Mo(CO)3(NCMe)3] affords the
reactive intermediate
[Me4N]2[Mo(CO)3{PhP(CH2CH2S)2}]
(1), which undergoes oxidation to afford
[Mo{PhP(CH2CH2S)2}2]
(2).
Reaction of 1 with a variety of dichloroalkanes
produces
[Mo(CO)3{c-PhP(CH2CH2S)2X}]
(X = CH2CH2,
CH2CH2CH2, CH2CHMe
or CH2CH(OH)CH2). The
structure of
[Mo(CO)3{c-PhP(CH2CH2S)2CH2CH2}]
(3) has
been established by X-ray crystallography and consists of a
Mo(CO)3 fragment facially coordinated by the
tridentate
c-PhP(CH2CH2S)2CH2CH2
ligand. Reaction of 3 with bromine affords
seven-coordinate
[Mo(CO)2{c-PhP(CH2CH2S)2CH2CH2}Br2]
(7), the X-ray crystal structure of which reveals a
carbonyl-capped octahedral geometry.
Treatment of 3 with sulfur results in loss of the
Mo(CO)3 fragment and isolation of
c-PhPS(CH2CH2S)2CH2CH2
(8), the X-ray structure of which shows a nine-membered ring
with the phosphorus center bearing phenyl and
sulfide substituents. Reduction of 8 with sodium
naphthalenide affords the parent ligand
c-PhP(CH2CH2S)2CH2CH2. Crystal data:  2,
C20H26MoP2S4,
triclinic P1̄, a = 8.105(3) Å,
b = 8.263(3) Å, c = 17.663(4) Å,
α =
100.29(2)°, β = 99.78(2)°, γ = 98.81(2)°,
Z = 2; 3,
C15H17MoO3PS2,
monoclinic P21/n, a =
9.600(3) Å, b =
15.594(5) Å, c = 11.335(3) Å, β =
93.01(2)°, Z = 4; 7,
C14H17Br2MoO2PS2,
monoclinic P21/c, a =
17.039(3)
Å, b = 8.686(2) Å, c = 12.466(3)
Å, β = 100.52(2)°, Z = 4; 8,
C12H17PS3, monoclinic
P21, a = 6.651(4) Å,
b
= 7.313(2) Å, c = 14.687(9) Å, β =
101.62(3)°, Z = 2.