Coordination geometry of lead carboxylates – spectroscopic and crystallographic evidence. Issue 5 (23rd December 2014)

• Record Type: Journal Article
• Authors: Catalano, Jaclyn; Murphy, Anna; Yao, Yao; Yap, Glenn P. A.; Zumbulyadis, Nicholas; Centeno, Silvia A.; Dybowski, Cecil
• Is Part Of: Dalton transactions. Volume 44:Issue 5(2015)
• Page Start: 2340
• Page End: 2347
• Publication Date: 2014-12-23
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c4dt03075c
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Spectroscopic and crystallographic data show lead carboxylate coordination is chain length dependent, shorter-chains (C6–C8) are hemidirected and longer-chains (C9–C18) are holodirected. Abstract : Despite their versatility, only a few single-crystal X-ray structures of lead carboxylates exist, due to difficulties with solubility. In particular, the structures of long-chain metal carboxylates have not been reported. The lone electron pair in Pb(ii ) can be stereochemically active or inactive, leading to two types of coordination geometries commonly referred to as hemidirected and holodirected structures, respectively. We report 13 C and 207 Pb solid-state NMR and infrared spectra for a series of lead carboxylates, ranging from lead hexanoate (C6) to lead hexadecanoate (C18). The lead carboxylates based on consistent NMR parameters can be divided in two groups, shorter-chain (C6, C7, and C8) and longer-chain (C9, C10, C11, C12, C14, C16, and C18) carboxylates. This dichotomy suggests two modes of packing in these solids, one for the short-chain lead carboxylates and one for long-chain lead carboxylates. The consistency of the 13 C and 207 Pb NMR parameters, as well as the IR data, in each group suggests that each motif represents a structure characteristic of each subgroup. We also report the single-crystal X-ray diffraction structure of lead nonanoate (C9), the first single-crystal structure to have been reported for the longer-chain subgroup. Taken together the evidence suggests that the coordination geometry of C6–C8 lead carboxylates is hemidirected, and that of C9–C14, C16 and C18 lead carboxylates is holodirected.