Synthesis, structure and properties of (4,4′-H2bipy)[HgBr4]·H2O with strong fluorescence

Influence of Aromatic Cations on the Structural Arrangement of Hg(II) Halides

“…In the three compounds, the monomeric Hg­(II) centers display a slightly distorted tetrahedral geometry ( 4 : τ 4 (Hg (1)) = 0.92; 5 : τ 4 (Hg (1)) = 0.91; 6 : τ 4 (Hg (1)) = 0.95) . The Hg–X bond lengths are within the range of reported (HgX 4 ) 2– anions ,− (Table ).…”

“…Even though it could not be considered a coordination bond, it is a non-negligible interaction since it directs the (HgBr 4 ) 2– stacking through the c axis and lengthens the Hg (1)–Br (3) bond (2.7985 (5) Å) compared to the rest (2.5491 (4)–2.6299 (4) Å). All the Hg–Br bond lengths are similar to the previously reported structure and within the range of other reported compounds with (HgBr 4 ) 2– anions and pyridinium cations (2.6328 (4)–2.6900 (5) Å) (Table ). In this case, the 2,2′-H 2 bipy rings are too far to assemble by π···π interactions (4.774 Å) (Figure b).…”

“…In 5 , two (1,10-Hphen) + cations associate with a (HgBr 4 ) 2– anion through double N–H···Br and C–H···Br interactions within the range of similar compounds (Table ). In addition, these anions are surrounded by (1,10-Hphen) + cations disposed in five pairs stacked by double (Figure a) or triple (Figure b) π···π interactions and a weak Br···π contact , (Figure c).…”

“…Notwithstanding the extensive research done with primary amines and in a lesser extent with aromatic rings, the studies incorporating pyridinium cations are scarce. , Howbeit, aromatic cations were proven to be remarkable candidates for preparing light-emitting compounds . While alkyl ammonium cations tend to form layered arrays, , even more pronounced with large cations, their replacement with bipyridinium rings with a delocalized π-electron character may, at the same time, modify the packing and the electronic properties.…”