Ammonium, alkylammonium, and amino acid complexes of a hexacopper fluoro-metallacrown cavitand

作者：Jones Leigh F; Barrett Simon A; Kilner Colin A; Halcrow Malcolm A^*

来源：Chemistry - A European Journal, 2008, 14(1): 223-233.

DOI：10.1002/chem.200701318

• complexation
• copper
• host-guest systems
• metallacrowns
• supramolecular chemistry

Reaction of CuF2 with one equivalent of 3{5}-(pyrid-2-yl)-5{3}-(tertbutyl)pyrazole (HL) and excess NH4OH in MeOH affords crystalline [NH4{Cu(mu-F)(mu-L)}(6)(CH2Cl2)2]HF2 in moderate yield. This compound contains the 12-MC-6 metallacrown [{Cu-(mu-F)(mu-L)}6] (1) with a NH4(+) ion at its center, and CH2Cl2 molecules complexed in bowl-shaped cavities above and below the CU6F6 ring. Similar reactions using the bases MeNH2, glycine, L-alanine or beta-alanine afforded solvated crystals of [1(H3NMe)(2)]Cl-2, [1-(gly)(2)], [1(L-ala)(2)], and [1(beta-ala)(2)], respectively. The metallacrown 1 in these products contains methylammonium and zwitterionic amino-acid guests in its two bowl-shaped cavities; each of the amino acids hydrogen-bonds to three F atoms. A related reaction using 1,6-diaminohexane resulted in fixation Of CO2 from the air to give solvated [1(H3NC6H12NHCO2)(2)], again with a zwitterionic guest. NMR, ESI-MS and UV/vis measurements suggest that the metallacrown 1 retains its integrity in several organic solvents, although it is unclear to what extent guest binding takes place in solution.

• 出版日期2008