The guest-dependent thermal response of the flexible MOF Zn-2(BDC)(2)(DABCO)

Abstract

The guest-dependent thermal response of the flexible MOF Zn-2(BDC)(2)(DABCO) (1) has been studied. A series of temperature-dependent single crystallographic analyses revealed inherent structural thermal responses of 1. The guest-free framework 1 exhibited interesting thermal responses including anisotropic thermal expansion (negative thermal expansion (NTE) along the a- and b-axes, positive thermal expansion (PTE) along the c-axis) and disorder-order phase transition. In addition, inclusion of guest molecules (DMF and benzene) brought distinct thermal responses to 1 from host-guest interactions. 1.4DMF showed altered thermal responses, presenting disorder-order phase transitions at a higher temperature and PTE along the a- and b-axes. Meanwhile, 1.3benzene displayed a quite different type of thermal response such as a hinge like motion (breathing) without a symmetry change.