Bis­(diethyl­enetri­amine-κ³N)­nickel hexa­fluoro­germanate

The title compound, [Ni(dien)₂][GeF₆] (dien is diethyl­enetri­amine, C₄H₁₃N₃), synthesized under mild solvothermal conditions, is a novel zero-dimensional material in which [GeF₆]²⁻ building anions are connected to [Ni(dien)₂]²⁺ cations via hydrogen bonds between F atoms and N—H groups. Both metal atoms are located on special positions of site symmetry 2/m. Furthermore, one F and one N atom (including the attached H atom) are located on a mirror plane.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.039
• wR factor = 0.119
• Data-to-parameter ratio = 13.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

Despite the rapid development in the syntheses of new materials, the field of fluorides remains undeveloped. More recently, fluoroaluminates such as (C₄H₁₂N₂)(H₃O)[Al₃F₁₂] (Tang et al., 2001c) and (C₄H₁₂N₂)₂[Al₂F₁₀]·2H₂O (Tang et al., 2001 e), the fluorosilicate of (C₄N₂H₁₂)[SiF₆] (Tang et al., 2001f) and fluorotitanates such as (C₅H₆N)₂(H₃O)[Ti₂F₁₁]·H₂O (Tang et al., 2001 d), (C₄N₂H₁₄)[TiF₄O] (Tang et al., 2001a), (C₄H₁₂N₂)[TiF₅(H₂O)]₂ (Tang et al., 2001b) and (C₄H₁₂N₂)₂[Ti₂F₁₀O]·2H₂O (Dadachov et al., 2001) have been reported. In those fluorides, the central Al, Si and Ti atoms are all completely coordinated by F atoms. Whereas considerably less work has been done on fluorogermanates, with only a few Ge^IV fluorides, viz. K₂[cis-(CF₃)₂GeF₄] (Brauer et al., 1980), [(CH₃)₄N][(CF₃)₃GeF₂] (Braueret al., 1986) and N(CH₂CH₂O)₃GeF (Lukevics et al., 1997), structurally characterized. All these fluorogermanates are coordinated by mixed ligands. Recently, the use of hydrofluoric acid as a mineralizing agent in the synthesis of zeolite materials with novel architectures has attracted much attention (Li et al., 1998; Plevert et al., 2001). As part of our interest in the borogermanate microporous materials, we tried to prepare novel open frameworks using organic amines in the presence of hydrofluoric acid. Unexpectedly, the novel title compound, (I), was obtained, which is the first structure of its kind.

The title compound (Fig. 1) is composed of [GeF₆]²⁻ anions and [Ni(dien)₂]²⁺ cations. As to the anion of [GeF₆]²⁻, each germanium center is coordinated by six fluoride ligands, resulting in an octahedral geometry, with Ge—F distances in the range 1.798 (2)–1.799 (4) Å, which is consistent with K₂GeF₆ (Ge—F = 1.77 Å; Hoard & Vincent, 1939), other fluorogermanates (Taylor & Wilson, 1973), and [(CH₃)₄N][(CF₃)₃GeF₂] (Brauer et al., 1986), and F—Ge—F angles between 89.4 (1) and 180°. The nickel cation displays distorted octahedral geometry and is bonded to six N atoms of two diethylene triamines with Ni—N distances in the range 2.110 (2)–2.112 (4) Å, and N—Ni—N angles in the range 83.1 (1)—180°. Like [Co(dien)₂]²⁺ (Keene & Searle, 1974), [Ni(dien)₂]²⁺ has also s-cis, u-cis and trans configurations, and the latter two are chiral. In the title compound, there is only one unique Ni site of s-cis-[Ni(dien)₂]²⁺. The [GeF₆]²⁻ anions interact with [Ni(dien)₂] ²⁺ cations both electrostatically and through weak hydrogen bonds. The hydrogen bonds are formed between the F and N atoms, with F···N distances in the range 3.060 (4)–3.180 (5) Å.

S2. Experimental

The title compound was prepared from a mixture of germanuim dioxide (GeO₂, 0.104 g) boric acid (H₃BO₃, 0.031 g), NiCl₂·6H₂O (0.238 g), diethylenetriamine (C₄N₃H₁₃, 2 ml), pyridine (C₅H₅N, 2 ml), hydrofluoric acid (HF, 40%, 0.1 ml), and deionized water (2 ml), in the molar ratio 1:1:1:18:25:5:110. The mixture was mechanically stirred completely at room temperature with a final pH of 9.0 and then placed in an autoclave at 443 K for 7 d.

S3. Refinement

All H atoms bonded to C and N atoms were positioned geometrically (C—H = 0.97 Å and N—H = 0.91 Å) and allowed to ride on their parent C or N atoms.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SHELXTL (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular components of the title complex, showing the atom-numbering scheme. Displacement ellipsoids are shown at the 30% probability level. [Symmetry codes: (i) 1/2 − x, 1/2 − y, z; (ii) 1/2 − x, 1/2 − y, 2 − z; (iii) x, y, 2 − z; (iv) 1/2 − x, 1/2 − y, 1 − z; (v) x, y, 1 − z.]
	Fig. 2. Packing diagram of (I), viewed down [101].

Bis(diethylenetriamine-κ³N)nickel hexafluorogermanate

Crystal data

[Ni(C4H13N3)2][GeF6]	F(000) = 920
Mr = 451.65	Dx = 1.902 Mg m^−3
Orthorhombic, Cccm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2 2c	Cell parameters from 25 reflections
a = 9.5937 (19) Å	θ = 2.5–25.0°
b = 15.193 (3) Å	µ = 3.17 mm^−1
c = 10.819 (2) Å	T = 293 K
V = 1576.9 (6) Å^3	Polyhedral, purple
Z = 4	0.48 × 0.40 × 0.22 mm

Data collection

Bruker CCD area-detector diffractometer	739 independent reflections
Radiation source: fine-focus sealed tube	536 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
ϕ and ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −11→8
Tmin = 0.238, Tmax = 0.498	k = −17→7
1847 measured reflections	l = −12→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.119	H-atom parameters constrained
S = 1.16	w = 1/[σ^2(Fo^2) + (0.0603P)^2 + 3.1056P] where P = (Fo^2 + 2Fc^2)/3
739 reflections	(Δ/σ)max < 0.001
57 parameters	Δρmax = 0.59 e Å^−3
0 restraints	Δρmin = −0.72 e Å^−3

Special details

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Ge	0.2500	0.2500	1.0000	0.0286 (3)
Ni	0.2500	0.2500	0.5000	0.0182 (3)
F2	0.3595 (2)	0.20270 (19)	1.1173 (2)	0.0479 (7)
F1	0.3582 (4)	0.3467 (3)	1.0000	0.0494 (10)
N1	0.1309 (3)	0.1877 (2)	0.6387 (3)	0.0287 (8)
H1A	0.1426	0.2162	0.7108	0.034*
H1B	0.0399	0.1904	0.6185	0.034*
N2	0.3596 (5)	0.1294 (3)	0.5000	0.0271 (11)
H2A	0.4525	0.1416	0.5000	0.033*
C1	0.1721 (5)	0.0957 (3)	0.6534 (5)	0.0408 (11)
H1C	0.1134	0.0587	0.6022	0.049*
H1D	0.1596	0.0781	0.7388	0.049*
C2	0.3259 (5)	0.0835 (3)	0.6159 (4)	0.0413 (11)
H2B	0.3853	0.1056	0.6814	0.050*
H2C	0.3451	0.0212	0.6061	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ge	0.0138 (5)	0.0512 (6)	0.0208 (5)	−0.0018 (4)	0.000	0.000
Ni	0.0144 (6)	0.0219 (5)	0.0184 (6)	0.0002 (4)	0.000	0.000
F2	0.0303 (14)	0.0757 (18)	0.0377 (15)	0.0025 (13)	−0.0096 (12)	0.0078 (14)
F1	0.026 (2)	0.062 (2)	0.060 (2)	−0.0089 (18)	0.000	0.000
N1	0.0203 (18)	0.0380 (18)	0.0277 (18)	0.0012 (15)	0.0031 (14)	0.0056 (15)
N2	0.017 (2)	0.033 (2)	0.032 (3)	0.000 (2)	0.000	0.000
C1	0.042 (3)	0.035 (2)	0.045 (3)	−0.004 (2)	0.009 (2)	0.012 (2)
C2	0.043 (3)	0.036 (2)	0.044 (3)	0.012 (2)	−0.002 (2)	0.012 (2)

Geometric parameters (Å, º)

Ge—F2^i	1.798 (2)	N1—C1	1.460 (5)
Ge—F2^ii	1.798 (2)	N1—H1A	0.9000
Ge—F2	1.798 (2)	N1—H1B	0.9000
Ge—F2^iii	1.798 (2)	N2—C2^iv	1.471 (5)
Ge—F1^ii	1.799 (4)	N2—C2	1.471 (5)
Ge—F1	1.799 (4)	N2—H2A	0.9100
Ni—N1^iii	2.110 (3)	C1—C2	1.542 (7)
Ni—N1^iv	2.110 (3)	C1—H1C	0.9700
Ni—N1^v	2.110 (3)	C1—H1D	0.9700
Ni—N1	2.110 (3)	C2—H2B	0.9700
Ni—N2	2.112 (4)	C2—H2C	0.9700
Ni—N2^v	2.112 (4)
F2^i—Ge—F2^ii	90.2 (2)	N1—Ni—N2^v	96.9 (1)
F2^i—Ge—F2	89.8 (2)	N2—Ni—N2^v	180.0
F2^ii—Ge—F2	180.0	C1—N1—Ni	111.1 (2)
F2^i—Ge—F2^iii	180.0	C1—N1—H1A	109.4
F2^ii—Ge—F2^iii	89.8 (2)	Ni—N1—H1A	109.4
F2—Ge—F2^iii	90.2 (2)	C1—N1—H1B	109.4
F2^i—Ge—F1^ii	90.6 (1)	Ni—N1—H1B	109.4
F2^ii—Ge—F1^ii	89.4 (1)	H1A—N1—H1B	108.0
F2—Ge—F1^ii	90.6 (1)	C2^iv—N2—C2	116.9 (5)
F2^iii—Ge—F1^ii	89.4 (1)	C2^iv—N2—Ni	107.6 (3)
F2^i—Ge—F1	89.5 (1)	C2—N2—Ni	107.6 (3)
F2^ii—Ge—F1	90.6 (1)	C2^iv—N2—H2A	108.2
F2—Ge—F1	89.4 (1)	C2—N2—H2A	108.2
F2^iii—Ge—F1	90.6 (1)	Ni—N2—H2A	108.2
F1^ii—Ge—F1	180.0	N1—C1—C2	110.3 (3)
N1^iii—Ni—N1^iv	180.0	N1—C1—H1C	109.6
N1^iii—Ni—N1^v	90.6 (2)	C2—C1—H1C	109.6
N1^iv—Ni—N1^v	89.4 (2)	N1—C1—H1D	109.6
N1^iii—Ni—N1	89.4 (2)	C2—C1—H1D	109.6
N1^iv—Ni—N1	90.6 (2)	H1C—C1—H1D	108.1
N1^v—Ni—N1	180.0	N2—C2—C1	112.2 (4)
N1^iii—Ni—N2	96.9 (1)	N2—C2—H2B	109.2
N1^iv—Ni—N2	83.1 (1)	C1—C2—H2B	109.2
N1^v—Ni—N2	96.9 (1)	N2—C2—H2C	109.2
N1—Ni—N2	83.1 (1)	C1—C2—H2C	109.2
N1^iii—Ni—N2^v	83.1 (1)	H2B—C2—H2C	107.9
N1^iv—Ni—N2^v	96.9 (1)	N1—C1—C2	110.3 (3)
N1^v—Ni—N2^v	83.1 (1)	N2—C2—C1	112.2 (4)

Symmetry codes: (i) x, y, −z+2; (ii) −x+1/2, −y+1/2, −z+2; (iii) −x+1/2, −y+1/2, z; (iv) x, y, −z+1; (v) −x+1/2, −y+1/2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···F1^vi	0.90	2.24	3.060 (4)	152
N1—H1B···F2^vi	0.90	2.37	3.099 (4)	138
N1—H1A···F2^ii	0.90	2.23	3.123 (5)	171
N2—H2A···F2^vii	0.91	2.39	3.180 (5)	145
N2—H2A···F2^viii	0.91	2.39	3.180 (5)	145

Symmetry codes: (ii) −x+1/2, −y+1/2, −z+2; (vi) x−1/2, −y+1/2, z−1/2; (vii) −x+1, y, z−1/2; (viii) −x+1, y, −z+3/2.