Room-temperature synthesis of a new stable (N₂H₄)WO₃ compound: a route for hydrazine trapping

A new (N₂H₄)WO₃ compound has been obtained by mixing WO₃ and aqueous hydrazine solution at room temperature for 24 h. The reaction is catalyzed by the presence of lithium. X-ray, synchrotron and neutron diffraction techniques have shown that the material crystallizes in trigonal space group P3₂21 (No. 154). Chains of distorted WO₄ tetrahedra extend along the a axis of the unit cell, linked by a corner-sharing oxygen atom: the N₂H₄ are in the voids between them. The thermal characterization shows that this new compound is stable up to 220°C, greatly beyond the boiling point of N₂H₄ (114°C); thus making it a promising candidate for catalysis or trapping applications.

Computing details

Program(s) used to refine structure: FULLPROF.

N2H4WO3

Crystal data

H4N2O3W	V = 268.87 (1) Å^3
Mr = 263.88	Z = 3
Trigonal, P3221	Neutron radiation
Hall symbol: P 32 2"	T = 100 K
a = 5.79842 (12) Å	white-bluish
c = 9.2341 (3) Å

Data collection

TOF diffractometer POWGEN	Scan method: time of flight
Radiation source: spallation source, POWGEN	2θfixed = 90.0000
Specimen mounting: 'powder in V container'

Refinement

Rp = 1.856	3121 data points
Rwp = 1.487	70 parameters
Rexp = 0.770	2 restraints
RBragg = 4.446

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
W	0.00000	0.1921 (5)	0.33333	0.00222*
O1	0.1949 (5)	0.1949 (5)	0.50000	0.0100 (7)*
O2	0.2351 (5)	0.4920 (6)	0.2537 (2)	0.0054 (4)*
N	0.74930 (18)	0.74272 (13)	0.57895 (13)	0.0065 (3)*
H1	0.6138 (8)	0.7952 (10)	0.6124 (6)	0.0254 (8)*
H2	0.6738 (12)	0.5512 (4)	0.6141 (6)	0.0254 (8)*