Synthesis, characterization and crystal structures of 1,7-dioxa-4-thia-10-azacyclododecane ([12]aneNO2S) and [Hg([12]aneNO2S)(NO3)2]

Abstract

Reaction of 6-(4-methylphenylsulfonyl)-1,11-bis(4-methylphenylsulfonyloxy)-3,9-dioxa-6-azaundecane and ethane-1,2-dithiol in the presence of NaH, results after removal of the protecting group, in the unexpected isolation of the twelve-membered macrocycle 1,7-dioxa-4-thia-10-azacyclododecane,[12]aneNO₂S. The product, suggested to arise from the intramolecular displacement of a tosyl group by a thioether instead of the terminal thiol as in the expected ring closing procedure, was characterised by ¹³C NMR spectroscopy, mass spectrometry, microanalysis and a single-crystal X-ray structure determination. The macrocycle crystallizes in the monoclinic space group P2₁, with a= 7.448(5), b= 5.1740(10), c= 12.769(9)Å, β= 93.28(2)°, Z= 2 with R= 0.046. All the donors in the macrocyclic ring are in the endodentate conformation with close contacts between the N–H and atoms O(1) and O(7). Reaction of mercury nitrate with 1 molar equivalent of [12]aneNO₂S in methanol, and subsequent crystallization of the product, resulted in colourless prisms of [Hg([12]aneNO₂S)(NO₃)₂] which crystallize in the monoclinic space group P2₁/c, with a= 9.165(17), b= 10.657(15), c= 14.80(2)Å, β= 92.57(8)°, Z= 4 with R= 0.055. In this molecule the mercury(II) cation is co-ordinated by the macrocyclic donors and the nitrate anions, one in a bidentate manner, the other in a monodentate mode.