Apparent molal volumes V-phi have been determined from density measurements for several aqueous solutions of 1,3,5,7-tetraazatricyclo[3.3.1.1(3,7)]decane (HMT) and 1,3.6,8-tetraazatricyclo[4.4.1.1(3,8)]dodecane (TATD) at T=(275.15, 275.65, 276.15, 276.65, 277.15. 277.65 and 278.15) K as function of composition. The infinite dilution partial molar volumes of solutes in aqueous solution are evaluated through extrapolation. Interactions of the solutes with water are discussed in terms of the effect of the temperature on the volumetric properties and the structure of the solutes. The results are interpreted in terms of water structure-breaking or structure forming character of the solutes. (C) 2011 Elsevier Ltd. All rights reserved.