Scrambling of Metal Precursors: A Strategy to Synthesize Trinuclear [M3(µ-Se)2(dppe)3]2+ (M = Ni, Pd) and Pentanuclear [Pd5(μ3-Se)4(dppe)4]2+ Coordination Clusters

Reaction of [PdCl 2 (dppe)] with two equivalents of the sodium salt of pyridyl selenolate afforded cis configured complex [Pd{2-SeC 5 H 3 (5-R)N} 2 (dppe)] (R = H, Me). The latter complexes on reacting with two equivalent of [NiCl 2 (dppe)] yielded an edge centered trinuclear complex [Ni 3 (μ-Se) 2 (dppe) 3 ]Cl 2 ( 2 ) and homometallic pentanuclear aggregates of composition [Pd 5 (μ 3 -Se) 4 (dppe) 4 ][BPh 4 ] 2 ( 3 ). Interplaying the same reaction in 1:2 molar ratio with [Ni(SeC 5 H 4 N) 2 (dppe)] and [PdCl 2 (dppe)], resulted in trinuclear compounds [M 3 (μ-Se) 2 (dppe) 3 ] 2+ (M = Ni, Pd) and an unidentified insoluble matrix. All the synthesized complexes were characterized by 1 H, 13 C{ 1 H}, 31 P{ 1 H}, 77 Se{ 1 H} NMR, IR and microanalysis. The molecular structure of the complex [Pd{2-SeC 5 H 3 (5-Me)N} 2 (dppe)] and [Pd 5 (μ 3 -Se) 4 (dppe) 4 ][BPh 4 ] 2 were established through single crystal X-ray analysis. In complex [Pd 5 (μ 3 -Se) 4 (dppe) 4 ][BPh 4 ] 2 , the palladium metals occupied the corner of square pyramidal geometry and the Pd···Pd distance within the dimeric unit is 3.1087 Å whereas the axial palladium-equatorial distance are 3.363 Å and 3.067 Å.