A novel photochromic calcium-based metal–organic framework derived from a naphthalene diimide chromophore

A novel 3D calcium-based metal-organic framework based on a naphthalene diimide chromophore has been synthesized which displays a unique doubly interpenetrated 7-connected net with total point symbol of {3(6)·4(9)·5(6)}. Excellent thermal stability and reversible photochromic properties have been observed in this compound.