We have prepared a series of N-picolyl-1,8-naphthalimide derivatives and explored their coordination chemistry with d-block metal ions in the solid and solution states,and exploited the structural and chemical propert...We have prepared a series of N-picolyl-1,8-naphthalimide derivatives and explored their coordination chemistry with d-block metal ions in the solid and solution states,and exploited the structural and chemical properties of these ligands to generate a family of robust metallogels.The 2-picolyl substituted ligands N-(2-picolyl)-1,8-naphthalimide L1 and N-(2-picolyl)-4-nitro-1,8-naphthalimide L2 showed interesting coordination behaviour in Mn,Co and Zn complexes 1-5,chelating through the pyridyl nitrogen atom and naphthalimide oxygen atom with subsequent bond localisation in the imide ring,the first example of such coordination behaviour to be structurally characterised.The 3-picolyl substituted ligands N-(3-picolyl)-1,8-naphthalimide L3 and N-(3-picolyl)-4-nitro-1,8-naphthalimide L4 vary in their coordination behaviour;the 4-unsubstituted ligand L3 acts as a simple monodentate donor giving crystalline assemblies,while the 4-nitro analogue L4 instead forms robust metallogels on reaction with Mn^(II) or Co^(II).The gels were found to be thermally and chemically reversible under various stimuli,and similar materials could be generated by installing a piperidinyl substituent at the naphthalimide 4-position,giving intensely coloured gels.These results describe previously unknown coordination chemistry and physical properties of the widely-used 1,8-naphthalimide backbone,and outline the important role played by subtle geometric variations in the physical characteristics of supramolecular metallogels.展开更多
A new potential Zn^(Ⅱ)responsive Mn^(Ⅱ)-based MRI CA candidate derived from pyclen-3,9-diacetate(3,9-PC2A)has been synthesized and it possesses a di-(2-picolyl)amine(DPA)moiety as an active arm.The PC2A-DPA ligand w...A new potential Zn^(Ⅱ)responsive Mn^(Ⅱ)-based MRI CA candidate derived from pyclen-3,9-diacetate(3,9-PC2A)has been synthesized and it possesses a di-(2-picolyl)amine(DPA)moiety as an active arm.The PC2A-DPA ligand was found to form a thermodynamically stable complex with Mn^(Ⅱ)(log K_(MnL)=15.87(6)which translates into a pMn of 8.79)which also possesses outstanding inertness towards Zn^(Ⅱ)ion triggered transmetallation(t_(1/2)at pH=6.0 is 64.5 h).The[Mn(PC2A-DPA)]complex has a relatively high relaxation rate(3.11 s^(−1)at 1.41 T and 37℃for a 0.96 mM complex)which is not affected by the Zn^(Ⅱ)concentration directly,yet in the co-presence of 0.7 mM human serum albumin(HSA)the relaxation rate values(both R_(1)and R_(2))increased significantly(9.08 s^(−1)at 1.41 T and 37℃,for a 0.748 mM complex)owing to the efficient binding of the complex to the protein(log K_(aff)=3.5±0.1 M−1).The increase is large enough to visualize it by MR imaging using phantoms in vitro while preliminary in vivo MRI experiments confirmed that the glucose stimulated Zn^(Ⅱ)secretion(GSZS)can be visualized in the prostate of a healthy mouse.展开更多
基金the Irish Research Council(IRC)for a post-doctoral fellowship(GOIPD/2015/446 to CSH)Science Foundation Ireland(SFI)for SFI PI Awards(10/IN.1/B2999 and 13/IA/1865 to TG and TG13/IA/1926 to MM)+1 种基金SFI RFP G22226/RFP-1/MTR/3135(to MM),MPNS COST Actions MP1106 and MP1305,ESA(A0-99-075 and contract 4000115113)TCD Dean of Research Pathfinder Award(TG and CSH),the School of Chemistry,University of Southampton and the School of Chemistry,Trinity College Dublin for financial support.
文摘We have prepared a series of N-picolyl-1,8-naphthalimide derivatives and explored their coordination chemistry with d-block metal ions in the solid and solution states,and exploited the structural and chemical properties of these ligands to generate a family of robust metallogels.The 2-picolyl substituted ligands N-(2-picolyl)-1,8-naphthalimide L1 and N-(2-picolyl)-4-nitro-1,8-naphthalimide L2 showed interesting coordination behaviour in Mn,Co and Zn complexes 1-5,chelating through the pyridyl nitrogen atom and naphthalimide oxygen atom with subsequent bond localisation in the imide ring,the first example of such coordination behaviour to be structurally characterised.The 3-picolyl substituted ligands N-(3-picolyl)-1,8-naphthalimide L3 and N-(3-picolyl)-4-nitro-1,8-naphthalimide L4 vary in their coordination behaviour;the 4-unsubstituted ligand L3 acts as a simple monodentate donor giving crystalline assemblies,while the 4-nitro analogue L4 instead forms robust metallogels on reaction with Mn^(II) or Co^(II).The gels were found to be thermally and chemically reversible under various stimuli,and similar materials could be generated by installing a piperidinyl substituent at the naphthalimide 4-position,giving intensely coloured gels.These results describe previously unknown coordination chemistry and physical properties of the widely-used 1,8-naphthalimide backbone,and outline the important role played by subtle geometric variations in the physical characteristics of supramolecular metallogels.
基金the financial support from the Hungarian National Research,Development and Innovation Office(NKFIH K-120224,134694 and FK-134551 projects)the University of Debrecen Innovation Fund(POC-012)+3 种基金the János Bolyai Research Scholarship of the Hungarian Academy of Sciences(G.T.and F.K.K.)supported by the UNKP-18-4 new national excellence program of the Ministry of Human Capacities(G.T.and F.K.K.)by the EU and co-financed by the European Regional Development Fund under the project GINOP-2.3.2-15-2016-00008Richárd Botár and Eniko Madarasi were also supported by the Doctoral School of Chemistry at the University of Debrecen,Debrecen,Hungary.
文摘A new potential Zn^(Ⅱ)responsive Mn^(Ⅱ)-based MRI CA candidate derived from pyclen-3,9-diacetate(3,9-PC2A)has been synthesized and it possesses a di-(2-picolyl)amine(DPA)moiety as an active arm.The PC2A-DPA ligand was found to form a thermodynamically stable complex with Mn^(Ⅱ)(log K_(MnL)=15.87(6)which translates into a pMn of 8.79)which also possesses outstanding inertness towards Zn^(Ⅱ)ion triggered transmetallation(t_(1/2)at pH=6.0 is 64.5 h).The[Mn(PC2A-DPA)]complex has a relatively high relaxation rate(3.11 s^(−1)at 1.41 T and 37℃for a 0.96 mM complex)which is not affected by the Zn^(Ⅱ)concentration directly,yet in the co-presence of 0.7 mM human serum albumin(HSA)the relaxation rate values(both R_(1)and R_(2))increased significantly(9.08 s^(−1)at 1.41 T and 37℃,for a 0.748 mM complex)owing to the efficient binding of the complex to the protein(log K_(aff)=3.5±0.1 M−1).The increase is large enough to visualize it by MR imaging using phantoms in vitro while preliminary in vivo MRI experiments confirmed that the glucose stimulated Zn^(Ⅱ)secretion(GSZS)can be visualized in the prostate of a healthy mouse.
