Hybrid Polymeric Iodoplumbates Constructed from Morpholine and Its Derivatives: Structures and Properties

Abstract

Three hybrid polymeric iodoplumbates constructed from morpholine and its derivatives, {(Pb₄I₁₅)[(Mph·H)₃(Mph·1.5H)₂]}_n(1), {(edm-H₂)(Pb₃I₈)]·2DMF}_n(2), {(edm-H₂)[(dmp)(Pb₄I₁₂)]˙2DMF}_n (3) (Mph = morpholine, edm = ethylenedimorpholine, dmp²⁺ = N,N′- dispiromorpholinopiperazonium) have been synthesized and structurally determined. In these compounds, morpholine and its derivatives weakly interact with or covalently bond to polymeric iodoplumbates. In 1, hydrogen bonds between (Pb₄I₁₅)⁷⁻ clusters and protonized Mph contribute to the formation of a 1-D hybrid chain. In 2, the 1-D [(Pb₃I₈)]_n²ⁿ⁻ chain is extended to be a 2-D layer via the edm²⁺ ligand by means of Pb–O covalent bonds. Interestingly, the 2-D [(Pb₄I₁₂)]_n⁴ⁿ⁻ inorganic layer in 3 is concertedly templated by two kinds of organic cations. The above compounds exhibit a semiconductor nature, and third-order nonlinear optical (NLO) activities can be detected in 1 and 3.