Bioinspired manganese(II) complexes with a clickable ligand for immobilisation on a solid support.
Clickable ligands like N,N'-bis((pyridin-2-yl)methyl)prop-2-yn-1-amine (L(1)) and N-((1-methyl-1H-imidazol-2-yl)methyl)-N-(pyridin-2-ylmethyl)prop-2-yn-1-amine (L(2)) have been used to synthesise a series of manganese(ii) complexes for grafting onto appropriate solid supports. These ligands mimic the 2-His-1-carboxylate facial chelation present in the active site of the manganese-dependent dioxygenase (MndD), while the alkyne side function allows grafting of the ligand onto an azido-functionalised support using "click chemistry" methodologies. Such synthetic analogues of the MndD crystallise in the solid state as double halide or pseudohalide-bridged dinuclear manganese(ii) complexes of the general formula [Mn2(μ-X)2X2L2] [L = L(1) with X = Cl (), Br (), and N3 (); L = L(2) with X = N3 ()]. Complexes are characterised by a weak magnetic exchange interaction between the two high-spin Mn(II) ions through the two X(-) bridges (J in the range of -0.059 to +5.30 cm(-1), H = -J·SMn1·SMn2 with SMn1 = SMn2 = 5/2). A new magneto-structural correlation of superexchange bis(μ1,1-azido)dimanganese(ii) complexes has been proposed using both structural parameters, the Mn-N-Mn bridging angle and the Mn-Nazido distance. In MeOH-EtOH solution the dimeric species are present together with few percents of mononuclear manganese(ii) complexes as evidenced by electron paramagnetic resonance (EPR) spectroscopy. Grafting the complexes onto mesoporous silica of MCM-41 type stabilises both dimers and monomers in the nanopores of the solid.
Instituto de Ciencia Molecular, Universitat de València, C/Catedrático José Beltrán 2, 46980 Paterna, València, Spain. isabel.castro@uv.es.
Jérémy
J
Chaignon
Salah-Eddine
SE
Stiriba
Francisco
F
Lloret
Consuelo
C
Yuste
Guillaume
G
Pilet
Laurent
L
Bonneviot
Belén
B
Albela
Isabel
I
Castro
D020134:Catalytic Domain; D057930:Click Chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D049308:Dioxygenases / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008024:Ligands; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D012822:Silicon Dioxide / Q000737:chemistry*; D060327:Solid-Phase Synthesis Techniques
D056831:Coordination Complexes; D008024:Ligands; C509968:MCM-41; D008345:Manganese; D012822:Silicon Dioxide; D049308:Dioxygenases