Nickel−Manganese Sulfido Carbonyl Cluster Complexes. Synthesis, Structure, and Properties of the Unusual Paramagnetic Complexes Cp₂Ni₂Mn(CO)₃(μ₃-E)₂, E = S, Se

Abstract

The reaction of Mn(2)(CO)(7)(mu-S(2)) with [CpNi(CO)](2) yielded the paramagnetic new compound Cp(2)Ni(2)Mn(CO)(3)(mu(3)-S)(2) (1) and a new hexanuclear metal product Cp(2)Ni(2)Mn(4)(CO)(14)(mu(6)-S(2))(mu(3)-S)(2) (2). Structurally, compound 1 contains two triply bridging sulfido ligands on opposite sides of an open Ni(2)Mn triangular cluster. EPR and temperature-dependent magnetic susceptibility measurements of 1 show that it contains one unpaired electron. The electronic structure of 1 was determined by Fenske-Hall molecular orbital calculations which show that the unpaired electron occupies a low lying antibonding orbital delocalized unequally across the three metal atoms. The selenium homologue Cp(2)Ni(2)Mn(CO)(3)(mu(3)-Se)(2) (3) was obtained from the reaction of a mixture of Mn(2)(CO)(10) and [CpNi(CO)](2) with elemental selenium and Me(3)NO.2H(2)O. It also has one unpaired electron. Compound 1 reacted with elemental sulfur to yield the dinickeldimanganese compound, Cp(2)Ni(2)Mn(2)(CO)(6)(mu(4)-S(2))(mu(4)-S(5)), 4, which can also be made from the reaction of Mn(2)(CO)(7)(mu-S(2)) with [CpNi(CO)](2) and sulfur. Compound 4 was converted back to 1 by sulfur abstraction using PPh(3). The reaction of Mn(2)(CO)(10) with [CpNi(CO)](2) in the presence of thiirane yielded the ethanedithiolato compound CpNiMn(CO)(3)(mu-SCH(2)CH(2)S) (5), which was also obtained from the reaction of Mn(4)(CO)(15)(mu(3)-S(2))(mu(4)-S(2)) with [CpNi(CO)](2) in the presence of thiirane. Compound 5 reacted with additional quantities of thiirane to yield the new compound CpNiMn(CO)(3)[mu-S(CH(2)CH(2)S)(2)], 6, which contains a 3-thiapentanedithiolato ligand that bridges the two metal atoms. Compound 6 was also obtained from the reaction of Mn(2)(CO)(10) with [CpNi(CO)](2) and thiirane. The molecular structures of the new compounds 1-6 were established by single-crystal X-ray diffraction analyses.

Effect of Pyramidalization of the M2(SR)2 Center: The Case of (C5H5)2Ni2(SR)2

“…As mentioned in older publications, previous examples of thiolates Cp 2 Ni 2 (SR) 2 and related phosphides Cp 2 Ni 2 (PR 2 ) 2 conform to the classical expectations of the 18e rule . These compounds feature planar M 2 (μ-X) 2 cores (X = SR, PR 2 ) and do not exhibit paramagnetism.…”

“…The shape and symmetry of Cp 2 Ni 2 (SEt) 2 MOs can be rationalized on the basis of a fragment-based correlation diagram, as popularized by Hoffmann, Hall, and their co-workers . The molecular orbitals of the Cp 2 Ni 2 (SEt) 2 system, in the C i configuration, result from a combination of the MOs of the Ni 2 S 2 planar core and the e 1 ″ and a 1 ″ MOs of the C 5 H 5 fragment (Supporting Information).…”

Rational Design of Fe2(μ‐PR2)2(L)6 Coordination Compounds Featuring Tailored Potential Inversion

“…In agreement with previous observations, [42,43] the LUMO of 1 has both an FeÀ Fe and FeÀ P (σ*) character, and therefore reduction results in an increase of both the FeÀ Fe distance and (albeit to a lesser extent) the FeÀ P distance. Reduction leads also to an increase in the Fe-PÀ P-Fe torsion angle (θ; often referred to as "hinge" or "flap" angle, [43,[64][65][66] i. e. a decreased pyramidalization; Figure 1, top).…”

QTAIM View of Metal–Metal Bonding in Di- and Trinuclear Disulfido Carbonyl Clusters

“…The synthesis of Mn 2 (μ-S 2 )(μ-CO)(CO) 6 ( 3 ), closely related to 1 , was initially reported by Adams and co-workers in 2001. Compound 3 has proved a useful reagent for heterometallic cluster synthesis, while reactions with phosphanes or arsanes lead to tetrasulfido-Mn 4 species resulting from cluster expansion reactions …”