Synthesis and characterization of organometallic macrocyclic rhodium (Ⅲ) complex with pyrazine ligands

The synthesis and structure research of organometal-lic macrocyclic complexes has been a very active field of modern chemistry [1—3]. In this field, Pd2+, Pt2+ complexes were first used as the building block, connected by het-erocyclic ligands, to construct metal macrocyclic com-pound[4,5]. The fac-Re(CO)5X (X = Cl, Br) fragment, for example, was shown to be a versatile building block for the synthesis of metallamacrocycles[6]. Some of this kind of molecule have been found applications in…

Synthesis and characterization of organometallic macrocyclic rhodium (III) complex with pyrazine ligands

The reaction of half-sandwich complex (Cp^tt Rh) ₂Cl ₂( μ -Cl)₂ (1) (Cp^tt = η⁵-^tBu₂C₅H ₃) with 1 equiv. of AgSO₃CF₃ in CH₂Cl₂ affords tri-μ-chloro dirhodium (2) cation compound, with 2 equiv. of AgSO₃CF₃ providing di-μ-chloro complex 3. The reaction of 3 with pyrazine gives a novel tetra-nuclear 14-member organometallic macrocyclic complex 4. FT-IR, ¹H-NMR, and EA were used to characterize these complexes. The structures of complexes 2 and 4 are confirmed by X-ray analysis. In complex 2, the two Cp^tt ring and tri-chloro atoms faces are approximately parallel to each other. In complex 4, the complex cation has a rectangular cavity with the dimension of 0.3748 nm×0.7027 nm, and the two-pyrazine rings are parallel to each other with a distance of 0.3510 nm.