Discussion
Hie extensive pioneering studies of Pedersen [ 1 ] has led to a virtual explosion of solution and solid-state investigation of crown ethers with metal ions. The metal ions include allrali metal, alkali earth metal, other main-group and transition-metal ions. We now report the crystal structure of another 15-crown- 5 2~ complex anion (figure, top and middle, respectively). In the complex anion, the Pd2 atom is coordinated by four Ν atoms from four NO2 groups. The N3-Pd2-N3', N4-Pd2-N4" bond angles are both 180°, implying the [Pd(NC>2) 4] 2~ anion has square planar configuration. The mean Pd2-Ν and Ν-Ο bond lengths are 2. ).
Discussion
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