Abstract
Two types of layered lanthanum phosphonates have been prepared and characterized by XRD, TGA, NMR and ER. The one form ed at pH< 3 has a composition of LaH(C>3 PR)2 (R= CH3, C2H 5 , C^Hs) and the other prepared at pH > 8 has the composition of La2 (0 3 PR)3 3 H2 O. Single crystals of lanthanum phenylphosphonate, L aH tO sP C ^H s^ were obtained and its structure determ ined. The structure is a layered one in which the La atoms are 8 -coordinate. The phenyl rings protrude into the interlam ellar space. Two copper phosphonates, Cu(0 3 PCH3 ) H 2O and CufC^PC^Hs) H 2O, have been synthesized and their structures determ ined. Cu(0 3 PC H 3 ) H 2O is layered with a interlayer distance of 8.5 A. Each Cu atom is 5-coordinated in a distorted tetragonal pyram idal configuration. Cu((>jPC6 H 5 ) H2O is also a layered com pound w ith an interlayer distance of 13.99 A. The coordination about the copper atoms and the layer structure are identical to those of the m ethvlphosphonate com pound. D ehydration of layered copper phosphonates Cu(0 3 PR)*H2 0 (R=CH3 , C6 H 5, CH 2C6H 5 ) yields layered anhydrous salts Cu(C>3PR) which show an increase of m ore than 1 A in interlayer spacing com pared to its monohydrate. Prim ary amines CnH 2 n+iN H 2 (n=3-8) were intercalated into Cu(0 3 PCH3> and Cu(0 3 PC6 H 5 ). The copper m ethylphosphonate takes up 1 mole of am ine form ing Cu(C>3 PC H 3 ) (RNH2 ), while 2 moles of amine were absorbed by copper phenylphosphonate. The alkyl chains of the am ine are packed as double layers w ith a tilt angle of 53° w ith respect to the mean plane of the layer. Both dehydrated and hydrated zinc phenylphsophonates are reactive towards prim ary amines. 1 mole of amine is intercalated forming layered com pound w ith composition of Zn(0 3 PC6 Hs) (RN H 2 ) in both cases. Two lanthanide phosphites, CeH(C>3 PH)2 2 H 2O and LaH(C>3PH)2 3 H 2O were prepared and their structures determined. Both of the structures are layered. Each lanthanide atom is 8 -coordinated by 7 phosphite oxygen atoms and 1 w ater molecule. The rest of water molecules reside between the layers.
Zhang, Yiping (1993). Synthesis and structural characterization of layered metal phosphonates, metal phosphites, and their intercalation compounds. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1531367.