Tetraammonium Tetrametaphosphimate Tetrahydrate

Vibrational analysis of Ag3(PO2NH)3, Na3(PO2NH)3.H2O, Na3(PO2NH)3.4H2O, [C(NH2)3]3(PO2NH)3.H2O and (NH4)4(PO2NH)4.4H2O

“…All the four modes of the NH 4 ion are found to be shifted from the free state values. This observation, in agreement with the structural reports, shows that the ion is distorted from the ideal tetrahedral geometry [24]. tetraguanidinium tetra-m-imido-cyclotetraphosphate tetrahydrate [C(NH 2 ) 3 ] 4 (PO 2 NH) 4 .4H 2 O also shows a highly intense IR band at 1659 cm − 1 due to 6 as CN [28].…”

“…Both the asymmetric and symmetric stretching modes of PO 2 in compound V appear a little lower in frequency when compared to all the other four compounds. This is due to the greater value of the average P O bond length in compound V than that in all the other compounds [24]. The bending modes of PO 2 group are observed around 600 cm − 1 .…”

“…For the preparation of (NH 4 ) 4 (PO 2 NH) 4 .4H 2 O (compound V), the starting material H 4 (PO 2 NH) 4 .2H 2 O was obtained according to the literature [6] by hydrolysis (333 K, 48 h) of (PNCl 2 ), in dioxane. Then an aqueous solution of ammonia (10%) is added to a stoichiometric amount of the acid followed by precipitation with acetone [24].…”

“…The broadening (: 250 cm − 1 ) of the 6 1 mode indicate the participation of the NH 4 ions in the formation of different types of hydrogen bonds N H---N and N H---O of varying strength [27]. The struc-tural investigation of compound V [24] reports that the NH 4 ions take part in extended hydrogen bonding by bridging, via, the lone pairs of OW2, N4 H42---OW2---H31 N3 (N---O---N 2.801, 2.858 A , ). The observation of strong IR band extending from about 3700 to 2700 cm − 1 (FWHM :720 cm − 1 ) also supports this.…”