Anions effect construction of 1D naphthalene diimide supramolecular chains by π interactions and fluorescence detect iodide anion.

Five diverse 1D supramolecular chains, {[4-pmntd]}n(1), {H2[4-pmntd]•2Br-}n(2), {H2[4-pmntd]•2NO3-}n(3), {H2[4-pmntd]•2ClO4-}n(4), {H2[4-pmntd]•2BF4-}n(5), (where 4-pmntd was N,N'-bis (4-pyridylmethyl)naphthalene diimide) were synthesized and characterized by X-ray single-crystal structure analysis, IR spectroscopy, elemental analyses, thermogravimetric analyses, fluorescence detection. The anions effect construction of their 1D chain structural diversity through different π interactions. Compound 1 through the adjacent pyridine rings parallel π∙∙∙π interactions formed 1D linear chain structure. Compound 2 through Br- anion∙∙∙π interactions and halogenbond interactions formed 1D zigzag chain structure. Compound 3 through lone pair∙∙∙π interactions of naphthalene diimide and the adjacent carboxyl group formed 1D stairway chain structure. Compound 4 through ClO4- anion∙∙∙π interactions formed 1D ribbon chain structure. Compound 5 through parallel π∙∙∙π interactions of the adjacent naphthalene diimide planes and pyridine rings formed 1D ladder chain structure. The five compounds' fluorescence properties and thermal stabilities were investigated. The compound 2 solution could fluorescence detection for iodide anion via fluorescence quenching.