From the reactions between M2(OCH2 tBu)6 (2 equiv) and NaP(SiMe3)2 (1 equiv) in benzene and 18-crown-6 the phosphinidine clusters M4(μ3-PSiMe3)(OCH2 tBu)11-, compounds 1 (M = Mo) and 2 (M = W) are ...formed and are reactive intermediates in the formation of M4(μ3-P)(OCH2 tBu)10- cluster anions, compounds 3 (M = Mo) and 4 (M = W), respectively, which have been isolated and characterized as their Na(18-crown-6)+ salts. Crystals of Na(18-crown-6)+Mo4(μ3-P)(OCH2 tBu)10-·C6H6 were examined by single crystal X-ray crystallography at −110 °C in the space group Pn with a = 13.000(2) Å, b = 17.501(3) Å, c = 18.703(2) Å, and β = 93.11(1)° with Z = 2 and at −173 °C in the space group Cc with a = 22.118(4) Å, b = 17.480(3) Å, c = 23.250(4) Å, and β = 110.82(1)° with Z = 4. At the lower temperature, there is higher symmetry and no disorder of the 18-crown-6 molecule. The cluster anion has a Mo4 butterfly with a μ3-P ligand and virtual mirror symmetry. One wing-tip Mo atom is five-coordinate and bonded to the μ3-P atom and shows longer Mo-to-Mo distances (2.68(1) and 2.71(1) Å) relative to its counterpart (2.48(1) and 2.50(1) Å); the backbone Mo−Mo distance is 2.53(1) Å. The cluster anion in 3 but not 4 is also accessible from the reaction between Mo2(OCH2 tBu)6 (2 equiv), PH3, and KOCH2 tBu (1 equiv) in THF/18-crown-6 (THF = tetrahydrofuran). A similar approach involving AsH3, Mo2(OCH2 tBu)6, and KOCH2 tBu gave the μ3-arsenide cluster complex K(18-crown-6)+Mo4(μ3-As)(OCH2 tBu)10-, compound 5, which by NMR spectroscopy is analogous in structure to 3. The reaction between Mo2(OCH2 tBu)6 (2 equiv) and KOH in THF/18-crown-6 gave K(18-crown-6)2 +Mo4(μ3-O)(OCH2 tBu)11-, compound 6, which is proposed to be isostructural with the phosphinidine complexes 1 and 2 on the basis of NMR data. Crystal data for K(η6-C12H24O6)(η2-C12H24O6)+Mo4(μ3-O)(OCH2 tBu)11- at −165 °C: a = 17.595(2) Å, b = 28.044(3) Å, c = 20.443(2) Å, β = 97.61(1)° with Z = 4, and space group P21/n. The cluster anion in 6 contains a 12-electron Mo4 butterfly with 12 M−M bonding electrons, as in 3, but the shortest Mo−Mo distance 2.42(1) Å involves the backbone metal atoms. The Mo−Mo distances involving the oxo-capped triangle (2.61(1) and 2.62(1) Å) are notably longer than those in the other triangle (2.48(1) Å).
From the reaction between Mo
2
(OCH
2
t
Bu)
6
and NaCp (Cp = C
5
H
5
) in THF the title complex was obtained as a crystalline product in the presence of DME (DME = dimethoxyethane). Crystal data for ...Mo
2
(OCH
2
t
Bu)
6
(Cp)Na(DME) at −167 °C: a = 11.885(2) Å, b = 19.240(1) Å, c = 11.562(2) Å, α = 102.73(1)°, β = 106.95(1)°, γ = 98.55(1)°, Z = 2 and space group of
. In the solid state there is an unbridged Mo≡Mo bond of distance 2.276(1) Å. One Mo atom is bonded to four alkoxides, two of which are also bonded to Na
+
while the other is η
5
-bonded to the Cp ligand, with MoC distances ranging from 2.34 to 2.66 Å, and to two OR groups, one of which is bound to the Na
+
ion. In addition to the coordination to three OR groups the Na
+
ion binds one DME molecule via both of its ether oxygen atoms. The MoO distances fall in the range 1.91-2.01 Å with the longer distances being associated with those groups that are also bonded to the Na
+
ion. In polar solvents the title complex dissociates to give Mo
2
(OCH
2
t
Bu)
6
and Na
+
Cp
−
. Key words: molybdenum, alkoxide, cyclopentadienyl, metal-metal triple bonds.
Rhenium(I) tricarbonyl (diphosphine) hydrides have been synthesized in high yield from one-pot reaction of Re
2(CO)
10 with diphosphines in refluxed pentanol.
The reactions of Re
2(CO)
10 with ...chelated diphosphines, P–P, where P–P are 1,3-bis(diphenylphosphino)propane (dppp), 1,4-bis(diphenylphosphino)butane (dppb), and 1,1′-bis(diphenylphosphino)ferrocene (dppfe), in refluxed 1-pentanol or 1-hexanol afford the corresponding hydrides
1–
3
fac-(CO)
3(P–P)ReH, (for
1, P–P is dppp, for
2, P–P is dppb, and for
3, P–P is dppfe) in high yield. The hydrides
1–
3 have been characterized spectroscopically and by X-ray crystal structure determinations.
Treatment of Re
2O
7 with manganese(I) and rhenium(I) hydrido {
fac-(CO)
3(PP)MH}, alkoxo {
fac-(CO)
3(PP)MOR}, methylcarbonato {
fac-(CO)
3(PP)MOC(O)OCH
3}, carbonato-bridged (CO)
3(PP)M
...2{μ-OC(O)O} and methoxymethyl {
fac-(CO)
3(PP)MCH
2OCH
3} complexes, where, R is CH
3 or CH
2CH
3, PP is dppe {1,2-bis(diphenylphosphino)ethane} or dppp {1,3-bis(diphenylphosphino)propane}, yielded the corresponding perrhenato complexes,
fac-(CO)
3(PP)MOReO
3 (
1, M=Mn, PP=dppe;
2, M=Mn, PP=dppp;
3, M=Re, PP=dppe;
4, M=Re, PP=dppp), in moderate to excellent yield. The perrhenato complexes have been characterized spectroscopically and the molecular structures of
fac-(CO)
3(dppp)MnOReO
3,
2 and
fac-(CO)
3(dppp)ReOReO
3,
4 have been established through X-ray crystallography.
Re
2O
7 reacts with manganese(I) and rhenium(I) hydrido, alkoxo, and related complexes to yield the corresponding M(I)Re(VII) complexes. The first X-ray crystal structure of a Mn(I)Re(VII) complex has been determined.
