Nitride fluoride

Nitride fluorides containing nitride and fluoride ions with the formula NF^4-. They can be electronically equivalent to a pair of oxide ions O₂^4-. Nitride fluorides were discovered in 1996 by Lavalle et al. They heated diammonium technetium hexafluoride to 300 °C to yield TcNF.^[1] Another preparation is to heat a fluoride compound with a nitride compound in a solid state reaction.^[2] The fluorimido ion is F-N^2- and is found in a rhenium compound.^[3]

name	formula	N:F ratio	system	space group	unit cell (Å)	volume	density	properties	references
dimagnesium fluoride nitride	L-Mg2NF	1:1	tetragonal	I41/amd	a = 4.186, c = 10.042			decompose over 1000 °C to MgF2, Mg gas and N2	[1][4]
	H-Mg2NF	1:1						H for 1250-1350 °C and 20 kbar	[1][4]
	Mg3NF3	1:3	cubic	Pm3m	a = 4.216			light green	[1][4]
dicalcium fluoride nitride	Ca2NF	1:1	cubic	Fd3m	a = 10.0215, Z = 16	1006.46	2.987	light yellow	[1]
dichromium fluoride nitride	Cr2NF3	1:3						dark green	[5]
dicobalt fluoride nitride	Co2NF	1:1							[1]
dicopper fluoride nitride	Cu2NF	1:1							[1]
	CaMgNF	1:1							[1]
	Fe4N3F3	1:1							[6]
α	Zn2NF	1:1	orthorhombic	P212121	a = 5.850, b = 5.892, c = 6.536			band gap 2.7 eV	[1]
β			tetragonal	P41212	a = 5.873, c = 6.532			band gap 2.8 eV
	Zn9N4F6	2:3						2 allotropes	[1]
	Zn7N4F	4:1							[1]
distrontium fluoride nitride	Sr2NF	1:1		Fd3m	a = 10.692, Z = 16			yellowish brown	[1][7]
				Fd3m	a = 10.765, Z = 16			dark red	[7]
	SrCaNF	1:1	cubic	Fd3m	a = 10.340, Z = 16	1105.6	3.862	yellow	[8]
	YNF3	1:3	hexagonal		a = 5.93, c = 4.79				[9]
	Zr4ON3F5	3:5	monoclinic	P1121/b	a = 5.1217, b = 21.513, c = 5.3669, γ = 90.128°, Z = 4
	ZrNF	1:1	monoclinic	P21/c	a = 5.227, b = 5.026, c = 5.191, β = 98.98°				[1]
	NaZr3N3F4	3:4		P63/mmc	a = 3.654, c = 18.266				[10]
	TcNF	1:1	hexagonal		a = 5.98, c = 4.79				[1]
dibarium fluoride nitride	Ba2NF	1:1		Fm3m	a = 5.679, Z = 2			dark violet	[11]
	LaNxF3(1-x}	x:3(1-x}	cubic		a = 5.847–5.871				[1]
	Ce3NF6	1:6			a = 5.8027			F− conductor	[12][2]
	Pr3NF6	1:6			a = 5.7723				[12]
	Gd3NF6	1:6	cubic		a = 5.617				[1]
	Ce2MnN3F2−δ		tetragonal	P4/nmm	a = 3.8554, c = 13.088			Nitridomanganate	[13]
	LiSr2[TaN3]F	3:1	orthorhombic	Pbca	a = 10.768, b = 5.591, c = 15.891, Z 8	956.7		Nitridotantalate, red, air sensitive	[14]
	ReNF	1:1	tetragonal		a = 5.88, c = 13.00				[1]
	Bi3NF6	1:6	orthorhombic	Pbcm	a = 5.8174, b = 5.7018, c = 18.5113, Z = 4	614.01	8.165	grey, moisture sensitive	[15]
	ThNF	1:1	rhombohedral		a = 7.13				[1]
	ThNxF4-3x		tetragonal					[1]
	UNxFy (UNF)	1:1	orthorhombic		a = 5.632–5.643, b = 5.602–5.610, c = 5.712–5.707				[1]
Complexes
	(AsPh+ 4)2[O2(TcNF2)2]2-	1:2						yellow, O-bridged	[16]
	Rb4[O(TcNF4)2]	1:4						orange yellow	[16]
	Cs4[O(TcNF4)2]	1:4						orange yellow	[16]
	H[TcNF4]	1:4							[16]
	(NEt4)3(NH4)[Tc4N4O4F8]							yellow green	[16]
molecules
phosphonitrile fluoride (trimer)	(NPF2)3	1:2	rhombohedral					triple point 27.8 °C; refractive index nα = 1.388, nβ = 1.419, nγ = 1.443	[17][18]
phosphonitrile fluoride (tetramer)	(NPF2)4	1:2	monoclinic					triple point 30.5 °C	[17]
poly-phosphonitrile fluoride	(NPF2)n	1:2							[17]
	ReNF3	1:3						brown	[19]
rhenium tetrafluoride nitride	ReNF4	1:4	orthorhombic		a = 5.64, b = 14.76, c = 4.26	354.6		yellow, molecular, mp 85 °C	[19]
fluoroimidorhenium pentafluoride	ReNF6	1:6	monoclinic		a = 5.298, b = 9.286, c = 9.979, β = 109.4, Z = 4	463.2	4.507	orange, molecular, N-F bonded, mp 80 °C	[19]