Polymorphism of Two‐Dimensional Semiconducting Coordination Polymers: Impact of a Lead–Sulfur Network on Photoconductivity

Abstract

AbstractSulfur‐coordinated coordination polymers (S−CPs) have unique optoelectrical properties that originate from infinite M−S bond networks. In this study, we synthesized and characterized two polymorphs of a two–dimensional (2D) Pb(II) S−CP with a formula of [Pb(tzdt)(OAc)] (Htzdt=1,3‐thiazolidine‐2‐thione, OAc=acetate). Our findings revealed that the thermodynamic product (KGF‐26) possesses quasi‐2D (−Pb−S−)n layers with weak nonbonded Pb−S bonds, whereas the kinetic product (KGF‐27) has intrinsic 2D (−Pb−S−)n layers with Pb−S bonds. The results of time‐resolved microwave conductivity measurements and first–principles calculations confirmed that KGF‐27 exhibits higher photoconductivity than KGF‐26, which establishes that the inorganic (−Pb−S−)n networks with Pb−S bonds are crucial for achieving high photoconductivity. This is the first experimental demonstration of the impact of the (−M−S−)n networks in S−CPs on photoconductivity through the comparison of crystal polymorphisms.