Syntheses, structures and magnetic properties of Mn(ii) dimers [CpMn(μ-X)]₂(Cp = C₅H₅; X = RNH, R¹R²N, CCR)

Abstract

Manganocene, Cp(2)Mn, has been employed as a precursor in the synthesis of a range of Mn(II) dimers of the type [CpMn(micro-X)](2)[X = 8-NHC(9)H(6)N (1), N(Ph)(C(5)H(4)N)(2), N(4-EtC(6)H(4))(C(5)H(4)N)(3) and C[triple bond]CPh (4)] as well as the bis-adduct [Cp(2)Mn[HN=C(NMe(2))(2)](2)](5). The solid-state structures of 1-5 are reported. Variable-temperature magnetic measurements have been used to assess the extent of Mn(micro-X)Mn communication within the dimers of 1-4 as a function of the bridging ligands (X).

Synthesis and Reactivity of an Early‐Transition‐Metal Alkynyl Cubane Mn4C4 Cluster

“…In comparison, the m 3 -H-bridged Mn 3 units in [MnH(hmds)] 6 are arranged in an early planar nanosheet geometry. [15] The m 3h 1 :h 1 :h 1 -bridging alkynyl metal motif is very well documented for the coinage metals Cu, Ag, and Au. [15] The m 3h 1 :h 1 :h 1 -bridging alkynyl metal motif is very well documented for the coinage metals Cu, Ag, and Au.…”

“…Te mperature-dependent magnetic measurements on solid 2 were in full agreement:S tarting at 6.1 cm 3 mol À1 Ka tr oom temperature, c M T decreased to almost zero at 15 K, indicating adiamagnetic S T = 0ground state (Figure 2). No m 3 -alkynyl Mn complexes have been reported previously.E ven for the simplest dinuclear m 2 -alkynyl complexes, [15,22] only one structure was magnetically characterized (J = À30.5 cm À1 , d(Mn-Mn) = 2.97 ). No m 3 -alkynyl Mn complexes have been reported previously.E ven for the simplest dinuclear m 2 -alkynyl complexes, [15,22] only one structure was magnetically characterized (J = À30.5 cm À1 , d(Mn-Mn) = 2.97 ).…”

Synthesis and Reactivity of an Early‐Transition‐Metal Alkynyl Cubane Mn4C4 Cluster

“…Zuschriften action through the two cubane faces with shorter Mn-Mn distances (3.08 )and J 2 (À10.4 cm À1 )through the four faces with longer Mn-Mn distances (3.23 ). No m 3 -alkynyl Mn complexes have been reported previously.E ven for the simplest dinuclear m 2 -alkynyl complexes, [15,22] only one structure was magnetically characterized (J = À30.5 cm À1 , d(Mn-Mn) = 2.97 ). [15b] Theo bserved coupling constants in 2 correlate well with the Mn-Mn distances and are much higher than for dinuclear Mn II complexes containing heteroatomic bridging ligands (phenoxides,h alides,a zides: j J j 5cm À1 ) [23] owing to the more covalent Mn À Cbond character.…”

“…[10] TheM n-C distances (2.21771(4), 2.27113(4), 2.31275 (7) )and CCbond lengths (1.22291(2) )i n2 are comparable with those of the bimetallic m 2 -h 1 :h 1 -alkynyl complexes [(nacnac)Mn(C CPh)] 2 and [CpMn(CCPh)(THF)] 2 (nacnac = HC-{CMeN(2,6-iPr 2 C 6 H 3 )} 2 ,C p = cyclopentadienyl). [15] The m 3h 1 :h 1 :h 1 -bridging alkynyl metal motif is very well documented for the coinage metals Cu, Ag, and Au. [11] Examples involving other transition metals are very rare,w ith only ah andful of s,m 3 -alkynyl complexes of the late transition metals Ru, Rh, and Ni reported.…”