Synthesis and crystal and molecular structures of diisopropyl N,N-diethylcarbamylmethylenephosphonate samarium nitrate and erbium nitrate complexes

Complexes of esters of ethylenediphosphonic acid with lanthanide nitrates—synthesis and structure

“…The considerably low frequency shift is comparable to the previously obtained complexes of alkylenediphosphonic esters [1] as well as in the complexes of carbamoylmethylphosphonates with lanthanide nitrates [15][16][17] and is an indication for bidentate coordination of the ligand 2. The charac-SCHEME 1 terization of the nitrate group in Nujol is based on the valence frequency ν 1 [1] at about 1300 cm −1 (see Table 1) and is in accordance with the data for other analogous complexes [15][16][17]. The band ν 2 is masked behind the strong P O C bonding vibration, and ν 4 in 3a and 3b is hidden more or less by a band of Nujol (1462 cm −1 in KBr).…”

“…The La ONO bond distances range from 2.6239(11) to 2.7296(3)Å and are similar to distances found in a number of lanthanide bidentate nitrate complexes [15,17].…”

Complexes of diethyl‐2‐amino‐2‐oxoethylphosphonate with lanthanide nitrates

“…This is in agreement with the data for lanthanide complexes with other carbamoyl phosphonate ligands [3,4,10]. The assignment of the amide CONH 2 frequency is complicated.…”

“…Horwitz and co-workers [14] have suggested that monodentate coordination through metal-phosphoryl oxygen occurs in solution of the complexes of dihexyl N,N-diethyl-carbamoylmethylenephosphonate (DHDECMP) with lanthanide and actinide ions. Similar monodentate coordination of the ligand and stabilization by a molecule of water is described for the complex of Er(NO 3 ) 3 and diisopropyl N-diethyl-carbamoylmethylphosphonate (DiDECMP) [3]. Unfortunately, till now we could not confirm the structure of the complexes 3 by X-ray diffraction analysis.…”

“…The signals for H3 and C3 (P CH 2 ) in methanol are not well resolved because of a slow exchange of the two protons, which is due to some flexibility around the central unit. The signal of C3 is not observed in some other carbamoylmethylphosphonate complexes as well [3]. 31 P, 13 C and 1 H NMR spectra of 3a, 3b, and 3c showed shifts downfield from the free ligand (see Table 2 for 13 C and Experimental section for 1 H), most significant by 3b in methanol ( δ C2 = 3.27 ppm, δ C O = 6.35 ppm, and δ 31 P = 6.03 ppm).…”