Synthesis and spectroscopic characterization of organometallic cluster macrocycles containing functionally bridged dicyclopentadienyl ligands.: Crystal structures of [Mo2Fe(μ3-S)(CO)7][η5-C5H4C(O)CH2]2, [W2Fe(μ3-S)(CO)7]2{[η5-C5H4C(O)CH2]2}2, and [Mo2Fe(μ3-S)(CO)7][η5-C5H4CH(OH)CH2]2

The self-assembly cyclization reactions of the diketo-containing carbon chain-bridged dicyclopentadienyl. M/Na salts [NaM(CO)(3)](2) [eta(5)-C5H4 C(O)CH2](2) (I, M = MO, W) with the same chain-bridged dicyclopentadienyl double clusters [MCoFe(mu(3)-S)(CO)(8)](2)[eta(5)-C5H4C(O)CH2](2) (II, M = Mo, W) were studied. While the reaction of I (M = Mo) with 11 (M = Mo) gave organometallic macrocycles containing a single and double [Mo2Fe(mu(3)-S)] cluster core, [Mo2Fe(mu(3)-S)(CO)(7)](n){ [eta(5)-C5H4C(O)CH2](2)}(n) (IIIa, n = 1; IVa, n = 2), I (M = W) reacted with II (M = W) to afford the macrocycles with a single and double [W2Fe(mu(3)-S)] cluster core [W2Fe(mu(3)-S)(CO)(7)](n){ [eta(5)-C5H4C(O)CH2](2)}(n) (IIIb, n = 1; IVb, n = 2). Further study on functional transformation reactions of these diketo-containing macrocycles indicated that IIIa,b and IVa,could react with NaBH4 to give dihydroxy-containing macrocycles having a single and double [M2Fe(mu(3)-S)] cluster core [M2Fe(mu(3)-S)(CO)(7)](2){[eta(5)-C5H4CH(OH)CH2](2) (Va, M = Mo; Vb, M = W) and [M2Fe(mu(3)-S)(CO)(7)](2){[eta(5)-C5H4CH(OH)CH2](2)}(2) (VIa, M = Mo; VIb, M = W). The structures of all the new macrocycles IIIa,b-VIa,b were characterized by elemental analyses and IR and H-1 NMR spectroscopy, whereas those of the representative clusters IIIa, IVb, and Va were unambiguously confirmed by X-ray diffraction techniques.