Extending the hydrogen-bonding array in ortho-phenylenediamine based bis-ureas

Two new ortho-phenylenediamine based bis-urea compounds have been synthesized with pendant amide groups. The stability constants of the new compounds with a variety of anionic guests have been measured by (1) H NMR titration techniques and compared to the parent bis-urea. The X-ray crystal structure of the acetate and benzoate complexes of a bis-amide functionalized system have been solved and reveal the receptor forming a dimer with two anions bound at the termini of the hydrogen bonded assembly.