A series of clip-shaped
cationic molecular corners C1~C4 (C1
= [(bpy)
2Pd
2(L
1)
2]
2+, C2 = [(dmbpy)
2Pd
2(L
1)
2]
2+, C3 = (bpy)
2Pd
2(L
2)
2]
2+, C4 = (dmbpy)
2Pd
2(L
2)
2]
2+, bpy = 2,2-bipyridine, dmbpy
= 4,4΄-dimethyl-2,2-bipyridine)
were synthesized through dipalladium complexes [(bpy)
2Pd
2(NO
3)
2](NO
3)
2,
[(dmbpy)
2Pd
2(NO
3)
2](NO
3)
2 and bifunctional pyrazole ligands 4-(3,4-dimethoxyphenyl)-3,5-dimethyl-1H-pyrazol
(HL
1) and 4,4΄-(5-(1H-pyrazol-4-yl)-1,3-phenylene)dipyridine
(HL
2). Complexes C1~C4 were characterized by
1H and
13C NMR, electrospray ionization mass spectrometry
(ESI-MS), elemental analysis, and IR spectroscopy. The X-ray diffraction
analysis of C1∙2NO
3− revealed a Pd
2 dimetallic clip-shaped structure which was
synthesized by two bifunctional ligands doubly bridged by the [(bpy)Pd]
2 dimetal units. Additionally, all of the complexes with NO
3− as counter anions exhibited high-efficiency
catalytical performance in
the Suzuki-coupling
reaction attributed to the tunable
impact and weak dinuclear Pd(II)···Pd(II) intramolecular bonding interaction.