Related Experiment Video
Updated: May 25, 2026
Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods
Published on: October 6, 2023
Multifunctional lanthanum tetraphosphonates: flexible, ultramicroporous and proton-conducting hybrid frameworks
Rosario M P Colodrero1, Pascual Olivera-Pastor, Enrique R Losilla
1Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos s/n, Málaga, 29071, Spain.
Abstract:
A new flexible ultramicroporous solid, La(H(5)DTMP)·7H(2)O (1), has been crystallized at room temperature using the tetraphosphonic acid H(8)DTMP, hexamethylenediamine-N,N,N',N'-tetrakis(methylenephosphonic acid). Its crystal structure, solved by synchrotron powder X-ray diffraction, is characterised by a 3D pillared open-framework containing 1D channels filled with water. Upon dehydration, a new related crystalline phase, La(H(5)DTMP) (2) is formed. Partial rehydration of 2 led to La(H(5)DTMP)·2H(2)O (3). These new phases contain highly corrugated layers showing different degrees of conformational flexibility of the long organic chain. The combination of the structural study and the gas adsorption characterization (N(2) and CO(2)) suggests an ultramicroporous flexible framework. NO isotherms are indicative of a strong irreversible adsorption of NO within the pores. Impedance data indicates that 1 is a proton-conductor with a conductivity of 8 × 10(-3) S cm(-1) at 297 K and 98% of relative humidity, and an activation energy of 0.25 eV.
