Tripodal naphthalene ether ligand: Solid-state anion recognition and fluorescence studies
摘要:
The simple tripodal amine ligand Tris-[2-(naphthalen-1-yloxy)-etliyl]-amine (L-1) was screened for anion recognition. Four crystal structures confirmed the inorganic as well as organic anion recognition in the solid state. Solid-state structures are results of supramolecular self-assembly and 3D molecular network involves C-H center dot center dot center dot O and C-H center dot center dot center dot pi bonding in the crystal lattice. In the solid state, it forms a strong C-H center dot center dot center dot Cl and C-H center dot center dot center dot O type interactions with the anions. This anion recognition was also confirmed by steady state fluorescence spectroscopy. In complex 4, L-1 is confined between 2D hydrogen bonded sheet formed by pyromellitic acid anion. L-1 shows unusually high selectivity toward nitrate in solution resulting in both a dramatic color change and a concomitant quenching of luminescence. (C) 2007 Elsevier B.V. All rights reserved.
Syntheses and crystal structures of tris[2-(1-naphthalenyloxy)ethyl]amine 1 and tris[2-(1-naphthalenyloxyl)ethyl] amine perchlorate 2 are reported. Compound 1 crystallizes in the rhombohedral system, space group R (3) over bar with a = 13.077(4), c = 29.011(8) Angstrom, and D-calc = 1.233g/cm(3) for Z = 6; compound 2 crystallizes in the cubic system, space group P2(1)3 with lattice parameters a = 14.630(5) Angstrom and D-calc = 1.332g/cm(3) for Z = 4. In 1, three naphthalene rings make dihedral angles of 109.21, 70.78, 70.78,degrees respectively. In 2 they make dihedral angles of 107.3, 72.7, 72.7 degrees respectively. Deviation of N from the plane (C(12),C(12)i,C(12)ii) in 1 is 0.3742 Angstrom which is less than that in (2) (-0.4223 Angstrom). The crystal structure is stabilized by van der Waals interactions in both compounds.