Structural Diversity Ranging from Oligonuclear Complexes to 1‐D and 2‐D Coordination Polymers Generated by Tetrasubstituted Adamantane and Spirobifluorene Derivatives. Issue 47 (12th December 2019) - Mocanu, Teodora
Abstract : Using tetrahedral and tetragonal spacers, seven new complexes have been obtained: [Co(hfac)2 (L 1 )0.5 ] 1, [Cu2 (hfac)4 L 2 ] 2, [Co(hfac)2 L 2 ] 3, [Co(hfac)2 (L 2 )0.5 ]· 8H2 O 4, [AgL 2 ](SbF6 )· CH3 COOC2 H5 5, [Mn(hfac)2 (L 3 )0.5 ] 6, [Zn(OAc)2 (L 3 )0.5 ] 7, {L 1 = 1, 3, 5, 7‐tetrakis(4‐cyanophenyl)adamantane, L 2 = 2, 2′, 7, 7′‐tetracyano‐9, 9′‐spirobifluorene and L 3 = 2, 2′, 7, 7′‐tetra(4‐pyridyl)‐9, 9′‐spirobifluorene, Hhfac = hexafluoroacetylacetone}. Compound 1 exhibits a 2‐D grid‐like structure with the tetradentate spacer acting as a 4‐connecting ligand. The 2, 2′, 7, 7′‐tetrasubstituted‐spirobifluorene derivatives connect the {M II (hfac)2 } entities into a binuclear complex (2 ), a linear chain (3 ) and diamond chains (4, 6 ). The cis or trans configuration of the metal nodes influences the overall topology (M II = Cu II, Co II, Mn II ). Similarly, a 1‐D double chain topological motif results by linking zinc ions and L 3 in compound 7 . Compound 5 is a 2‐D coordination polymer featuring a layered framework with square cavities. Compound 5 undergoes a reversible single‐crystal‐to‐single‐crystal process, with removal of the solvent molecules (ethyl acetate). The luminescence properties of compounds 5, 7 have been investigated and reveal blue emission with maxima at 402 and 483 nm, respectively. The dynamic magnetic properties and EPR spectrum of 1 have been investigated, revealing the occurrence of slow relaxation of the magnetization that most likely involves a Raman process. Abstract : Adamantane and spirobifluorene functionalized with coordinating groups are employed as ligands with various metal ions (Ag +, Zn 2+, Co 2+, and Mn 2+ ), resulting in oligonuclear and coordination polymers.