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In the title compound, (NH4)[IrCl2(C4H7N2O2)2], (I), the Ir atom is octahedrally coordinated by two trans Cl- and two di­methyl­glyoximate chelate ligands in the equatorial plane. A two-dimensional hydrogen-bond network between ammonium cations NH4+ and anionic [IrCl2(C4H7N2O2)2]- complexes is extended along the bc plane.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010000038X/qb0165sup1.cif
Contains datablocks I, irdmg

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S010827010000038X/qb0165Isup2.hkl
Contains datablock I

CCDC reference: 142927

Comment top

Among compounds of the elements in Group 9 with dimethylglyoxime (H2dmg), cobalt complexes, the so-called cobaloximes, have been well studied from the bioinorganic aspects as useful vitamin B12 models (Randaccio et al., 1989). Some rhodium complexes are known, but have not been often applied to biological investigation in comparison with the cobalt complexes. The cobaloximes and rhodoximes commonly have octahedral geometry with equatorial coordination of two Hdmg anions. As for the iridium complex, more inert than the rhodium, the structure of [IrCl2(Hdmg)(H2dmg)], (II), was only reported (Simonov et al., 1996); the geometry about iridium is octahedral, similar to the cobaloximes and rhodoximes. Its properties remain unexplored owing to the low solubility in solvents. We attempted to derive salts by replacement of onium ions such as NH4+, NBu4+ etc. in order to examine chemical and physical properties in solutions. Single crystals of the ammonium salt, (NH4)[IrCl2(Hdmg)2], (I), were obtained from ethanol solution.

The crystal structure of (I) is constructed of NH4+ cations and octahedral [IrCl2(Hdmg)2] anions. The iridium atom on the inversion center is coordinated by two Cl atoms in trans and two Hdmg chelate ligands in the equatorial plane, similarly to (II). A pair of the Hdmg are planar with a maximum deviation of 0.138 (5) Å of C4 and linked with each other by the O1···H7—O2 intramolecular hydrogen bonds to form a 14-membered macrocycle. The intermolecular hydrogen bonds between the oxime groups of the [IrCl2(Hdmg)2] moieties are observed in (II) but not in (I). Insteadly, two-dimensional hydrogen-bond network along the bc plane is formed between NH4+ and, Cl and O1 atoms of [IrCl2(Hdmg)2] moieties.

The notable difference between (II) and (I) is found in the O—N distances of the Hdmg moieties. In (I), the O1—N1 distance [1.323 (3) Å] is distinctly shorter than the O2—N2 distance [1.380 (3) Å], while the O—N distances of the two independent molecules in (II) are within a small range (1.36–1.37 Å). The discrepancy of the O—N distances in (I) shows that the H atom is strongly bonded to the O2 atom; such a phenomenon has been found in the cobaloximes or rhodoximes, e.g. [Rh(Hdmg)2(H2O)2](ClO4) (Moszner et al., 1997). In (I), the O—N distances seem quite close to each other owing to the delocalized distribution of the protonated oxime groups. Other bond distances and angles are reasonable within the standard deviations.

Experimental top

The protonated iridoxime, [IrCl2(Hdmg)(H2dmg)], (II), was prepared according to the procedure reported by Simonov et al. (1996). To the suspended aqueous solution of (II), ammoniac water was added to precipitate fine crystals of (NH4)[IrCl2(Hdmg)2], (I). By replacing ammoniac water with 10% methanol solution of NBu4OH, precipitate of (NBu4)[IrCl2(Hdmg)2], (III), soluble in organic solvents such as CH2Cl2, CH3CN etc., was obtained. Attempts to substitute the axial Cl ligands with AgCl or NaBH4 have been unsuccessful.

The single crystals of (I) were obtained from ethanol solution of the precipitate by absorbing vaporized ether. Analysis found: C 18.52, H 3.50, N 13.86%; calculated for C8H18Cl2IrN5O4: C 18.79, H 3.55, N 13.69%.

1H NMR of (III) [CDCl3, 300 MHz, δ p.p.m.) 5.36 (s, 2H, OH), 2.40 (s, 12H, CH3), 3.18 (t, 8H, CH2(NBu4)], 1.58 [quintet, 8H, CH2(NBu4)], 1.40 [sextet, 8H, CH2(NBu4)], 0.99 [t, 12H, CH3(NBu4)]. The spectrum is consistent with the octahedral geometry of anionic complex of (I).

Refinement top

Refined C—H distances are in the range 0.91 (4)–0.96 (4) Å.

Computing details top

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1993a); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN PROCESS (Molecular Structure Corporation, 1993b); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

(I) top
Crystal data top
(NH4)[IrCl2(C4H7N2O2)2]F(000) = 976
Mr = 511.37Dx = 2.273 Mg m3
Dm = 2.27 Mg m3
Dm measured by flotation in CCl4/CBr4
Monoclinic, C2/cMo Kα radiation, λ = 0.71069 Å
a = 18.3948 (13) ÅCell parameters from 25 reflections
b = 7.4649 (14) Åθ = 14.7–15.0°
c = 13.2477 (16) ŵ = 9.31 mm1
β = 124.752 (4)°T = 296 K
V = 1494.6 (3) Å3Prism, intense green
Z = 40.15 × 0.15 × 0.11 mm
Data collection top
Rigaku AFC-7R
diffractometer
1686 reflections with I > 2σ(I)
Radiation source: rotating Mo anticathodeRint = 0.014
Graphite monochromatorθmax = 30.0°, θmin = 2.7°
ω/2θ scansh = 2125
Absorption correction: ψ scan
(North et al., 1968)
k = 010
Tmin = 0.282, Tmax = 0.359l = 180
2266 measured reflections3 standard reflections every 150 reflections
2177 independent reflections intensity decay: none
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.014All H-atom parameters refined
wR(F2) = 0.035 w = 1/[σ2(Fo2) + (0.0167P)2 + 1.024P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
2177 reflectionsΔρmax = 0.57 e Å3
130 parametersΔρmin = 0.75 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.00299 (8)
Crystal data top
(NH4)[IrCl2(C4H7N2O2)2]V = 1494.6 (3) Å3
Mr = 511.37Z = 4
Monoclinic, C2/cMo Kα radiation
a = 18.3948 (13) ŵ = 9.31 mm1
b = 7.4649 (14) ÅT = 296 K
c = 13.2477 (16) Å0.15 × 0.15 × 0.11 mm
β = 124.752 (4)°
Data collection top
Rigaku AFC-7R
diffractometer
1686 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.014
Tmin = 0.282, Tmax = 0.3593 standard reflections every 150 reflections
2266 measured reflections intensity decay: none
2177 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0140 restraints
wR(F2) = 0.035All H-atom parameters refined
S = 1.05Δρmax = 0.57 e Å3
2177 reflectionsΔρmin = 0.75 e Å3
130 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

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 (Å2) top
xyzUiso*/Ueq
Ir0.00000.50000.00000.01648 (5)
Cl0.09255 (4)0.57499 (11)0.06226 (6)0.03066 (14)
O10.01829 (13)0.1423 (2)0.09772 (17)0.0307 (4)
O20.11906 (13)0.8025 (3)0.14412 (19)0.0319 (4)
N10.05479 (14)0.3033 (3)0.12534 (18)0.0206 (4)
N20.10257 (13)0.6226 (3)0.14552 (18)0.0210 (4)
C10.1770 (2)0.2074 (5)0.3320 (3)0.0349 (7)
C20.12787 (16)0.3419 (4)0.2317 (2)0.0231 (5)
C30.15551 (16)0.5294 (3)0.2429 (2)0.0213 (5)
C40.23678 (19)0.6037 (5)0.3550 (3)0.0301 (6)
N300.0810 (6)0.250.0373 (8)
H10.165 (2)0.094 (6)0.301 (3)0.038 (9)*
H20.156 (2)0.211 (5)0.378 (3)0.056 (11)*
H30.239 (3)0.234 (6)0.384 (3)0.062 (12)*
H40.241 (3)0.578 (7)0.427 (4)0.078 (14)*
H50.285 (3)0.555 (6)0.362 (4)0.065 (13)*
H60.239 (3)0.727 (7)0.352 (4)0.073 (14)*
H70.080 (3)0.832 (6)0.070 (4)0.069 (14)*
H80.012 (3)0.003 (5)0.204 (4)0.059 (13)*
H90.044 (3)0.146 (6)0.199 (4)0.073 (14)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ir0.01911 (7)0.01424 (6)0.01536 (6)0.00020 (6)0.00940 (5)0.00001 (5)
Cl0.0311 (3)0.0362 (3)0.0319 (3)0.0011 (3)0.0222 (3)0.0037 (3)
O10.0410 (11)0.0160 (9)0.0275 (9)0.0061 (8)0.0151 (8)0.0003 (7)
O20.0354 (11)0.0176 (9)0.0329 (10)0.0063 (8)0.0137 (9)0.0005 (8)
N10.0268 (10)0.0162 (10)0.0194 (9)0.0004 (8)0.0136 (8)0.0024 (8)
N20.0235 (9)0.0174 (10)0.0206 (9)0.0027 (8)0.0116 (8)0.0028 (8)
C10.0406 (17)0.0290 (16)0.0237 (13)0.0046 (13)0.0117 (13)0.0062 (12)
C20.0258 (11)0.0237 (13)0.0188 (11)0.0027 (10)0.0121 (9)0.0016 (9)
C30.0222 (10)0.0221 (15)0.0202 (10)0.0001 (9)0.0124 (9)0.0037 (9)
C40.0244 (12)0.0362 (17)0.0236 (12)0.0024 (12)0.0101 (10)0.0036 (12)
N30.053 (2)0.027 (2)0.038 (2)0.0000.030 (2)0.000
Geometric parameters (Å, º) top
Ir—N12.005 (2)C1—H10.91 (4)
Ir—N21.992 (2)C1—H20.90 (4)
Ir—Cl2.3437 (6)C1—H30.96 (4)
O1—N11.323 (3)C4—H40.92 (5)
O2—N21.380 (3)C4—H50.92 (5)
N1—C21.310 (3)C4—H60.92 (5)
N2—C31.290 (3)O2—H70.85 (4)
C1—C21.490 (4)N3—H80.96 (4)
C2—C31.468 (3)N3—H90.85 (4)
C3—C41.489 (4)
N1—Ir—N277.48 (8)C2—C1—H1111 (2)
N1—Ir—Cl90.38 (6)C2—C1—H2108 (2)
N2—Ir—Cl91.55 (6)H1—C1—H2105 (3)
C2—N1—O1123.0 (2)C2—C1—H3112 (2)
C2—N1—Ir116.9 (2)H1—C1—H3113 (3)
O1—N1—Ir120.0 (2)H2—C1—H3108 (3)
C3—N2—O2119.5 (2)C3—C4—H4113 (3)
C3—N2—Ir118.6 (2)C3—C4—H5109 (3)
O2—N2—Ir121.9 (2)H4—C4—H5108 (4)
N1—C2—C3113.7 (2)C3—C4—H6112 (3)
N1—C2—C1122.6 (3)H4—C4—H6106 (4)
C3—C2—C1123.6 (2)H5—C4—H6110 (4)
N2—C3—C2113.1 (2)N2—O2—H7103 (3)
N2—C3—C4123.6 (2)H8—N3—H9108 (4)
C2—C3—C4123.3 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H7···O1i0.85 (4)1.92 (4)2.755 (3)170 (4)
N3—H8···O10.96 (4)1.83 (4)2.781 (3)172 (4)
N3—H9···Clii0.85 (4)2.56 (5)3.294 (4)144 (4)
Symmetry codes: (i) x, y+1, z; (ii) x, y1, z.

Experimental details

Crystal data
Chemical formula(NH4)[IrCl2(C4H7N2O2)2]
Mr511.37
Crystal system, space groupMonoclinic, C2/c
Temperature (K)296
a, b, c (Å)18.3948 (13), 7.4649 (14), 13.2477 (16)
β (°) 124.752 (4)
V3)1494.6 (3)
Z4
Radiation typeMo Kα
µ (mm1)9.31
Crystal size (mm)0.15 × 0.15 × 0.11
Data collection
DiffractometerRigaku AFC-7R
diffractometer
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.282, 0.359
No. of measured, independent and
observed [I > 2σ(I)] reflections
2266, 2177, 1686
Rint0.014
(sin θ/λ)max1)0.704
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.014, 0.035, 1.05
No. of reflections2177
No. of parameters130
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.57, 0.75

Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1993a), MSC/AFC Diffractometer Control Software, TEXSAN PROCESS (Molecular Structure Corporation, 1993b), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997).

Selected geometric parameters (Å, º) top
Ir—N12.005 (2)O2—N21.380 (3)
Ir—N21.992 (2)N1—C21.310 (3)
Ir—Cl2.3437 (6)N2—C31.290 (3)
O1—N11.323 (3)C2—C31.468 (3)
N1—Ir—N277.48 (8)N2—Ir—Cl91.55 (6)
N1—Ir—Cl90.38 (6)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H7···O1i0.85 (4)1.92 (4)2.755 (3)170 (4)
N3—H8···O10.96 (4)1.83 (4)2.781 (3)172 (4)
N3—H9···Clii0.85 (4)2.56 (5)3.294 (4)144 (4)
Symmetry codes: (i) x, y+1, z; (ii) x, y1, z.
 

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