The phenoxido and alkoxido bridged neutral Zn3 complex [Zn3(mu-H2bemp)2(m3-emp)2](1), with an angular Zn3(mu-OPh)2(mu-OEt)2 core and capping nitrogen donors, was synthesized via simultaneous chelation-cum-bridging of the parent and hydrolysed ligands. Zinc(II) coordination triggered the solution phase imine (C=N) bond hydrolysis of H3bemp (2,6-bis-[(2-hydroxyethylimino)methyl]-4-methylphenol) and yielded the unexpected angular trinuclear Zn(II) complex 1, having structural similarity with the Zn3 active site of P1 nuclease. H3bemp also displays a zinc(II) selective chelation-enhanced fluorescence response from strong metal ion coordination. Complexation of zinc(II) with H3bpmp (2,6-bis-[(3-hydroxypropylimino)methyl]-4-methylphenol), a close analogue of H3bemp,instead provides only mononuclear [Zn(H2bpmpHN)2](ClO4)2·2H2O(2·2H2O) (HN is the proton attached to an imine nitrogen atom) of two zwitterionic ligands, generated through a kind of coordination driven acid–base reaction, without showing any aggregation reaction. As the sole metal–organic precursor, both the complexes under pyrolytic conditions give ZnO nano structures of two morphologies.
Coordination induced fluorescence enhancement and construction of a Zn3 constellation through hydrolysis of ligand imine arms
BERTOLASI, Valerio;
2012
Abstract
The phenoxido and alkoxido bridged neutral Zn3 complex [Zn3(mu-H2bemp)2(m3-emp)2](1), with an angular Zn3(mu-OPh)2(mu-OEt)2 core and capping nitrogen donors, was synthesized via simultaneous chelation-cum-bridging of the parent and hydrolysed ligands. Zinc(II) coordination triggered the solution phase imine (C=N) bond hydrolysis of H3bemp (2,6-bis-[(2-hydroxyethylimino)methyl]-4-methylphenol) and yielded the unexpected angular trinuclear Zn(II) complex 1, having structural similarity with the Zn3 active site of P1 nuclease. H3bemp also displays a zinc(II) selective chelation-enhanced fluorescence response from strong metal ion coordination. Complexation of zinc(II) with H3bpmp (2,6-bis-[(3-hydroxypropylimino)methyl]-4-methylphenol), a close analogue of H3bemp,instead provides only mononuclear [Zn(H2bpmpHN)2](ClO4)2·2H2O(2·2H2O) (HN is the proton attached to an imine nitrogen atom) of two zwitterionic ligands, generated through a kind of coordination driven acid–base reaction, without showing any aggregation reaction. As the sole metal–organic precursor, both the complexes under pyrolytic conditions give ZnO nano structures of two morphologies.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
