Synthesis and crystal structures of four pH-dependent Pb(II) and Cd(II) phosphonates based on a novel ligand, 3-phosphono-benzoic acid

Lead(II) Hybrid Materials from 3‐ or 4‐Phosphonobenzoic Acid

“…The thermogravimetric curves of 2 and 3 exhibit a first weight loss between room temperature to 210°C which is in good agreement with the departure of the coordinate water molecules present in the structure: 3.27 % for two H 2 O in 2 (theoretical loss:3.41 %), 1.73 % for two H 2 O in 3 (theoretical loss:1.73 %). For the thermogravimetric curve of 1 (data not shown), almost the same mass losses than those recently reported by Fang et al [22] were observed (our results: 3.32 % mass losses found between www.eurjic.org100°C and 210°C; theoretical mass losses for two molecules of water: 3.41 %). After this process of dehydratation, a series of several weight losses are observed which are attributed to the decomposition of the compound and to the formation of Pb 3 (PO 4 ) 2 .…”

“…The very recently reported [22] X-ray structure of Pb 3 (H 2 O) 2 (m-PO 3 C 6 H 4 CO 2 ) 2 (1) consists of a threedimensional mineral framework made of PbO n (n = 5, 6, 8) polyhedra sharing edges and apices. This framework consists of tunnels running along an axis in which the organic Scheme 1.…”

“…In the case of 1, the metal-oxygen-metal networks (see Figure S4 and ref. [22] ) clearly describe a 3D network (I 3 ). Regarding the description of the metal-ligand-metal linkage ( Figure S5) the situation is more complex for this compound and several points of view could be considered due to the sharing of the carboxylic and phosphonic function between several lead atoms.…”

“…On our side, we have investigated the use of 3-phosphonobenzoic acid as a rigid organic building block. [21] The use of this rigid organic precursor has also been illustrated by the recent works of Fang et al [22] In our previous study it is reported that the conditions of synthesis associated with the nature of the inorganic precursors give rise to hybrid structures where the link between the organic molecule and the inorganic network is achieved either by both functional groups or only by the phosphonic acid group. The critical factor, that governs the chemioselectivity observed, is the pH of the reac-tion media.…”

“…The exploration and the knowledge of the structure of such frameworks are of great interest to a better understanding of the physico-chemical properties of lead materials (e.g. luminescent properties [25] 2 (m-PO 3 C 6 H 4 CO 2 ) 2 ] (1) which has been obtained by using 3-phosphonobenzoic acid as organic precursor and for which the X-ray structure has been very recently reported by Fang et al [22] Finally the ATG and Scanning Electron Microscopy of all these materials are reported and discussed.…”