Langmuir−Blodgett Films Based on Known Layered Solids:  Lanthanide(III) Octadecylphosphonate LB Films

Abstract

Several lanthanide(III) octadecylphosphonate Langmuir−Blodgett (LB) films have been prepared and characterized. Films with La3+, Ce3+, Sm3+, and Gd3+ are formed one bilayer at a time using a Y-type deposition procedure that allows the metal phosphonate continuous lattice network to crystallize during the upstroke of the film transfer. Comparison of the phosphonate IR stretching modes of the LB films to those of known model solids shows that each film is an LB analogue of the powdered solid-state lanthanide butylphosphonates of formula LnIIIH(O3PC4H9)2 that possess a two-dimensional ionic covalent metal phosphonate network. X-ray photoelectron spectroscopy (XPS) shows that the P/Ln ratio in each of the transferred films is 2:1, which corresponds to the stoichiometry in the known layered materials, and X-ray diffraction (XRD) shows that the films are layered each with a bilayer thickness of 51 ± 1 Å. The behavior of octadecylphosphonic acid Langmuir monolayers on subphases containing each metal ion is studied as a function of pH, and general procedures for the deposition of metal phosphonate continuous lattice LB films are developed.

Structural Characterization and Magnetic Order in Phenoxy-Substituted Divalent Metal Phosphonate Langmuir–Blodgett Films

“…It has previously been shown that the phosphonate (P}O) infrared stretching modes can be used to correlate the metal}phosphonate continuous lattice structures of LB "lms with those of the solid-state structures (9). The P}O stretching frequencies are very sensitive to the mode of metal bonding (9,12,13,30), and the di!erent metal phosphonate structure types give distinct P}O stretching patterns in their IR spectra. Figure 3 shows the asymmetric phosphonate ( (PO\ )) and symmetric phosphonate ( (PO\ )) stretches, occurring at 1083.9 and 978.8 cm\ for the Mn-P4 LB "lm and at 1084.9 and 958.6 cm\ for the Cd-P4 "lm, respectively.…”

“…A variety of metal phosphonate LB "lms have been formed (7}9, 12,13) each possessing a known solid-state metal phosphonate structure type. LB "lms based on octadecylphosphonic acid (ODPA) with formulas M''(O PR)H O (M''"Mn>, Cd>, Co>, and Mg>) (9,12), M''(HO PR) (M''"Ca> or Ba>) (9,12), and¸n'''H(O PR) (¸n'''"La>, Ce>, Sm>, and Gd>) (12,13) have been prepared, where the inorganic network has the same structure as the analogous solidstate metal phosphonate of the same formula (10, 14 }17 continuous lattice structure (M''"Mn or Cd), and the magnetic properties of the manganese "lm are reported. These "lms are referred to as Mn-P4 and Cd-P4, where the P represents an alkoxyphenyl group and the 4 indicates the number of carbons separating the aryl group from the phosphonate head group.…”

Low dimensional organized hybrid structures containing europium complexes formed at the air/water interface

“…7. The absorption bands at 1223 and 1001 cm À 1 appearing in the spectrum of HP, correspond to the PMO stretch vibrations of free phosphate and hydrogen bonding species, respectively [17,18]. The band at 1223 cm À 1 is weaker than the band at 1001 cm À 1 , indicating that most HP molecules form hydrogen bonds in the pure HP film.…”

New phosphinate ligand synthesis and its effect on optical properties of the europium β‐diketonate complex

“…Fanucci and Talham prepared several metal phosphonate LB films based upon solid-state lanthanide (III) phos- phonates by Y-type deposition procedure; photoluminescent properties were investigated showing structural films characteristics [8].…”