Hydrothermal Synthesis, Crystal Structure and Optical Properties of [M(en) 3 ](ndt)·H 2 O (M=Ni II , Co II , Mn II and ndt=1,5‐Naphthalenedithiolate)

Three novel compounds [Ni(en) 3 ](ndt)·H 2 O ( 1 ), [Co(en) 3 ](ndt)·H 2 O ( 2 ) and [Mn(en) 3 ](ndt)·H 2 O ( 3 ) (en=ethylenediamine, ndt=1,5‐naphthalenedithiolate) have been synthesized under hydrothermal conditions. The structures were characterized by single crystal X‐ray diffraction and all belong to monoclinic space group Cc . The [M(en) 3 ] 2+ cations (M=Ni II , Co II , Mn II ), ndt anions and crystallized water molecules assemble an iso‐structural three‐dimensional network through H‐bonding interactions. Optical absorption properties and band gaps of such three compouds were determined with UV/Vis/NIR diffuse reflectance spectra.