The cation in the title compound, [Cr(NO)(NH3)5]Cl2, is distorted octahedral with a linear Cr-N-O moiety. The short Cr-N(nitrosyl) distance of 1.692 (7) Å indicates significant multiple bonding between these atoms. The Cr atom, the NO group and the N atom trans to NO have m2m symmetry and the remaining N and Cl atoms have m symmetry.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 273 K
- Mean (O-N) = 0.008 Å
- Disorder in main residue
- R factor = 0.044
- wR factor = 0.117
- Data-to-parameter ratio = 17.7
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Alert Level B:
PLAT_301 Alert B Main Residue Disorder ........................ 38.00 Perc.
Alert Level C:
PLAT_302 Alert C Anion/Solvent Disorder ....................... 50.00 Perc.
General Notes
FORMU_01 There is a discrepancy between the atom counts in the
_chemical_formula_sum and the formula from the _atom_site* data.
Atom count from _chemical_formula_sum:H15 Cl2 Cr1 N6 O1
Atom count from the _atom_site data: H12.5 Cl1 Cr0.25 N2.5 O0.25
ABSTM_02 When printed, the submitted absorption T values will be replaced
by the scaled T values. Since the ratio of scaled T's is
identical to the ratio of reported T values, the scaling does
not imply a change to the absorption corrections used in the
study.
Ratio of Tmax expected/reported 1.189
Tmax scaled 0.841 Tmin scaled 0.698
CELLZ_01
From the CIF: _cell_formula_units_Z 4
From the CIF: _chemical_formula_sum Cl2 Cr1 H15 N6 O1
TEST: Compare cell contents of formula and atom_site data
atom Z*formula cif sites diff
Cl 8.00 4.00 4.00
Cr 4.00 1.00 3.00
H 60.00 50.00 10.00
N 24.00 10.00 14.00
O 4.00 1.00 3.00
Difference between formula and atom_site contents detected.
ALERT: Large difference may be due to a
symmetry error - see SYMMG tests
CHEMW_03
From the CIF: _cell_formula_units_Z 4
From the CIF: _chemical_formula_weight 238.06
TEST: Calculate formula weight from _atom_site_*
atom mass num sum
Cr 52.00 0.25 13.00
N 14.01 2.50 35.02
O 16.00 0.25 4.00
Cl 35.45 1.00 35.45
H 1.01 12.50 12.60
Calculated formula weight 100.07
ALERT: The ratio of given/expected molecular weight as calculated
from the _atom_site* data lies outside
the range 0.90 <> 1.10
0 Alert Level A = Potentially serious problem
1 Alert Level B = Potential problem
1 Alert Level C = Please check
The preparation of [Cr(NO)(NH3)5]Cl2 was carried out according to the
literature method (Mori et al., 1963). Crystals of
[Cr(NO)(NH3)5]Cl2 were obtained by recrystallization from aqueous
hydrochloric acid.
All the H atoms were fixed in the refinement with isotropic displacement
parameters fixed at 1.2 times the value of the equivalent isotropic
displacement parameter of their carrier atom. Since the N2 atom is at a site
with m2m symmetry, the six disordered H atoms of the ammonia
molecule have been developed by mirror symmetry. The occupancy factors for N2
(at a site with m2m symmetry), H1 (at a site with mirror
symmetry) and H2 were set to 1/4, 0.25 and 1/2, respectively.
Data collection: CrystalClear (Rigaku, 1996); cell refinement: CrystalClear; data reduction: TEXSAN (Molecular Structure Corporation & Rigaku Corporation, 1999); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: TEXSAN; molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: TEXSAN.
Crystal data top
[Cr(NO)(NH3)5]Cl2 | F(000) = 492 |
Mr = 238.06 | Dx = 1.674 Mg m−3 Dm = 1.62 Mg m−3 Dm measured by flotation |
Orthorhombic, Cmcm | Mo Kα radiation, λ = 0.7107 Å |
Hall symbol: -C 2c 2 | Cell parameters from 1131 reflections |
a = 10.0236 (9) Å | θ = 3.0–27.5° |
b = 9.098 (3) Å | µ = 1.73 mm−1 |
c = 10.357 (1) Å | T = 273 K |
V = 944.5 (5) Å3 | Prism, orange |
Z = 4 | 0.20 × 0.10 × 0.10 mm |
Data collection top
Rigaku/MSC Mercury CCD diffractometer | 389 reflections with F2 > 2σ(F2) |
Detector resolution: 7.32 pixels mm-1 | Rint = 0.084 |
ω scans | θmax = 27.2° |
Absorption correction: multi-scan (TEXSAN; Molecular Structure Corporation & Rigaku Corporation, 1999) | h = −11→12 |
Tmin = 0.587, Tmax = 0.707 | k = −11→11 |
5457 measured reflections | l = −13→11 |
601 independent reflections | |
Refinement top
Refinement on F2 | H-atom parameters not refined |
R[F2 > 2σ(F2)] = 0.044 | w = 1/[σ2(Fo2) + (0.034P2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.117 | (Δ/σ)max < 0.001 |
S = 0.83 | Δρmax = 0.88 e Å−3 |
601 reflections | Δρmin = −0.48 e Å−3 |
34 parameters | |
Crystal data top
[Cr(NO)(NH3)5]Cl2 | V = 944.5 (5) Å3 |
Mr = 238.06 | Z = 4 |
Orthorhombic, Cmcm | Mo Kα radiation |
a = 10.0236 (9) Å | µ = 1.73 mm−1 |
b = 9.098 (3) Å | T = 273 K |
c = 10.357 (1) Å | 0.20 × 0.10 × 0.10 mm |
Data collection top
Rigaku/MSC Mercury CCD diffractometer | 601 independent reflections |
Absorption correction: multi-scan (TEXSAN; Molecular Structure Corporation & Rigaku Corporation, 1999) | 389 reflections with F2 > 2σ(F2) |
Tmin = 0.587, Tmax = 0.707 | Rint = 0.084 |
5457 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.044 | 34 parameters |
wR(F2) = 0.117 | H-atom parameters not refined |
S = 0.83 | Δρmax = 0.88 e Å−3 |
601 reflections | Δρmin = −0.48 e Å−3 |
Special details top
Refinement. Refinement using reflections with F2 > -10.0 σ(F2). The
weighted R-factor (wR) and goodness of fit (S) are based
on F2. R-factor (gt) are based on F. The threshold
expression of F2 > 2.0 σ(F2) is used only for calculating
R-factor (gt). |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Cr1 | 0.5000 | 0.3005 (1) | 0.7500 | 0.0167 (3) | 0.25 |
Cl1 | 0.2168 (1) | 0.5000 | 1.0000 | 0.0214 (3) | 0.50 |
O1 | 0.5000 | 0.6166 (7) | 0.7500 | 0.028 (2) | 0.25 |
N1 | 0.5000 | 0.4870 (7) | 0.7500 | 0.017 (2) | 0.25 |
N2 | 0.5000 | 0.0668 (7) | 0.7500 | 0.025 (2) | 0.25 |
N3 | 0.2926 (5) | 0.2834 (5) | 0.7500 | 0.023 (1) | 0.50 |
N4 | 0.5000 | 0.2890 (5) | 0.9513 (4) | 0.020 (1) | 0.50 |
H1 | 0.5894 | 0.0320 | 0.7500 | 0.0295* | 0.25 |
H2 | 0.4553 | 0.0320 | 0.8249 | 0.0295* | 0.50 |
H3 | 0.2678 | 0.1827 | 0.7500 | 0.0272* | 0.50 |
H4 | 0.2578 | 0.3299 | 0.8249 | 0.0272* | |
H5 | 0.5000 | 0.1890 | 0.9775 | 0.0246* | 0.50 |
H6 | 0.4226 | 0.3365 | 0.9840 | 0.0246* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cr1 | 0.0186 (6) | 0.0169 (7) | 0.0146 (6) | 0.0000 | 0.0000 | 0.0000 |
Cl1 | 0.0219 (6) | 0.0220 (7) | 0.0203 (6) | 0.0000 | 0.0000 | −0.0007 (5) |
O1 | 0.023 (3) | 0.038 (4) | 0.025 (3) | 0.0000 | 0.0000 | 0.0000 |
N1 | 0.018 (3) | 0.019 (4) | 0.014 (3) | 0.0000 | 0.0000 | 0.0000 |
N2 | 0.034 (4) | 0.017 (4) | 0.022 (4) | 0.0000 | 0.0000 | 0.0000 |
N3 | 0.023 (2) | 0.021 (3) | 0.024 (2) | −0.004 (2) | 0.0000 | 0.0000 |
N4 | 0.023 (2) | 0.018 (2) | 0.020 (2) | 0.0000 | 0.0000 | 0.000 (2) |
Geometric parameters (Å, º) top
Cr1—N1 | 1.697 (7) | N2—H2ii | 0.950 |
Cr1—N2 | 2.126 (7) | N2—H2i | 0.950 |
Cr1—N3 | 2.085 (4) | N2—H2iii | 0.950 |
Cr1—N3i | 2.085 (4) | N3—H3 | 0.950 |
Cr1—N4 | 2.087 (4) | N3—H4 | 0.950 |
Cr1—N4ii | 2.087 (4) | N3—H4ii | 0.950 |
O1—N1 | 1.179 (8) | N4—H5 | 0.950 |
N2—H1 | 0.950 | N4—H6 | 0.950 |
N2—H1i | 0.950 | N4—H6i | 0.950 |
N2—H2 | 0.950 | | |
| | | |
Cl1···N3 | 3.341 (3) | Cl1···N4 | 3.464 (3) |
Cl1···N3iv | 3.341 (3) | Cl1···N4iv | 3.464 (3) |
Cl1···N2v | 3.434 (2) | O1···N4iv | 3.211 (5) |
Cl1···N2vi | 3.434 (2) | O1···N4vii | 3.211 (5) |
Cl1···N4v | 3.448 (4) | O1···N3viii | 3.302 (5) |
Cl1···N4vi | 3.448 (4) | O1···N3ix | 3.302 (5) |
| | | |
N1—Cr1—N2 | 180.0 | H1—N2—H2i | 56.2 |
N1—Cr1—N3 | 94.3 (1) | H1—N2—H2iii | 56.2 |
N1—Cr1—N3i | 94.3 (1) | H1i—N2—H2 | 56.2 |
N1—Cr1—N4 | 92.9 (1) | H1i—N2—H2ii | 56.2 |
N1—Cr1—N4ii | 92.9 (1) | H1i—N2—H2i | 109.4 |
N2—Cr1—N3 | 85.7 (1) | H1i—N2—H2iii | 109.4 |
N2—Cr1—N3i | 85.7 (1) | H2—N2—H2ii | 109.5 |
N2—Cr1—N4 | 87.1 (1) | H2—N2—H2i | 56.2 |
N2—Cr1—N4ii | 87.1 (1) | H2—N2—H2iii | 141.0 |
N3—Cr1—N3i | 171.4 (3) | H2ii—N2—H2i | 141.0 |
N3—Cr1—N4 | 89.79 (1) | H2ii—N2—H2iii | 56.2 |
N3—Cr1—N4ii | 89.79 (1) | H2i—N2—H2iii | 109.5 |
N3i—Cr1—N4 | 89.79 (1) | Cr1—N3—H3 | 109.5 |
N3i—Cr1—N4ii | 89.79 (1) | Cr1—N3—H4 | 109.5 |
N4—Cr1—N4ii | 174.3 (3) | Cr1—N3—H4ii | 109.5 |
Cr1—N1—O1 | 180.0 | H3—N3—H4 | 109.5 |
Cr1—N2—H1 | 109.5 | H3—N3—H4ii | 109.5 |
Cr1—N2—H1i | 109.5 | H4—N3—H4ii | 109.5 |
Cr1—N2—H2 | 109.5 | Cr1—N4—H5 | 109.5 |
Cr1—N2—H2ii | 109.5 | Cr1—N4—H6 | 109.5 |
Cr1—N2—H2i | 109.5 | Cr1—N4—H6i | 109.5 |
Cr1—N2—H2iii | 109.5 | H5—N4—H6 | 109.5 |
H1—N2—H1i | 141.0 | H5—N4—H6i | 109.5 |
H1—N2—H2 | 109.4 | H6—N4—H6i | 109.4 |
H1—N2—H2ii | 109.4 | | |
Symmetry codes: (i) −x+1, y, z; (ii) x, y, −z+3/2; (iii) −x+1, y, −z+3/2; (iv) x, −y+1, −z+2; (v) x−1/2, y+1/2, z; (vi) x−1/2, −y+1/2, −z+2; (vii) x, −y+1, z−1/2; (viii) x+1/2, y+1/2, z; (ix) −x+1/2, y+1/2, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3···O1x | 0.95 | 2.75 | 3.302 (6) | 118 |
N3i—H3i···O1xi | 0.95 | 2.75 | 3.302 (6) | 118 |
N4—H6···O1xii | 0.950 | 2.894 | 3.211 (5) | 100.801 |
N4—H6i···O1xii | 0.950 | 2.894 | 3.211 (5) | 100.801 |
N4ii—H6ii···O1xiii | 0.950 | 2.894 | 3.211 (5) | 100.801 |
N4ii—H6iii···O1xiii | 0.950 | 2.894 | 3.211 (5) | 100.801 |
Symmetry codes: (i) −x+1, y, z; (ii) x, y, −z+3/2; (iii) −x+1, y, −z+3/2; (x) −x+1/2, y−1/2, z; (xi) x+1/2, y−1/2, z; (xii) x, −y+1, z+1/2; (xiii) x, −y+1, −z+1. |
Experimental details
Crystal data |
Chemical formula | [Cr(NO)(NH3)5]Cl2 |
Mr | 238.06 |
Crystal system, space group | Orthorhombic, Cmcm |
Temperature (K) | 273 |
a, b, c (Å) | 10.0236 (9), 9.098 (3), 10.357 (1) |
V (Å3) | 944.5 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.73 |
Crystal size (mm) | 0.20 × 0.10 × 0.10 |
|
Data collection |
Diffractometer | Rigaku/MSC Mercury CCD diffractometer |
Absorption correction | Multi-scan (TEXSAN; Molecular Structure Corporation & Rigaku Corporation, 1999) |
Tmin, Tmax | 0.587, 0.707 |
No. of measured, independent and observed [F2 > 2σ(F2)] reflections | 5457, 601, 389 |
Rint | 0.084 |
(sin θ/λ)max (Å−1) | 0.643 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.117, 0.83 |
No. of reflections | 601 |
No. of parameters | 34 |
No. of restraints | ? |
H-atom treatment | H-atom parameters not refined |
Δρmax, Δρmin (e Å−3) | 0.88, −0.48 |
Selected geometric parameters (Å, º) topCr1—N1 | 1.697 (7) | Cr1—N4 | 2.087 (4) |
Cr1—N2 | 2.126 (7) | Cr1—N4ii | 2.087 (4) |
Cr1—N3 | 2.085 (4) | O1—N1 | 1.179 (8) |
Cr1—N3i | 2.085 (4) | | |
| | | |
N1—Cr1—N2 | 180.0 | N3—Cr1—N3i | 171.4 (3) |
N1—Cr1—N3 | 94.3 (1) | N3—Cr1—N4 | 89.79 (1) |
N1—Cr1—N4 | 92.9 (1) | N4—Cr1—N4ii | 174.3 (3) |
N2—Cr1—N3 | 85.7 (1) | Cr1—N1—O1 | 180.0 |
N2—Cr1—N4 | 87.1 (1) | | |
Symmetry codes: (i) −x+1, y, z; (ii) x, y, −z+3/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3···O1iii | 0.950 | 2.750 | 3.302 (6) | 117.805 |
N3i—H3i···O1iv | 0.950 | 2.750 | 3.302 (6) | 117.805 |
N4—H6···O1v | 0.950 | 2.894 | 3.211 (5) | 100.801 |
N4—H6i···O1v | 0.950 | 2.894 | 3.211 (5) | 100.801 |
N4ii—H6ii···O1vi | 0.950 | 2.894 | 3.211 (5) | 100.801 |
N4ii—H6vii···O1vi | 0.950 | 2.894 | 3.211 (5) | 100.801 |
Symmetry codes: (i) −x+1, y, z; (ii) x, y, −z+3/2; (iii) −x+1/2, y−1/2, z; (iv) x+1/2, y−1/2, z; (v) x, −y+1, z+1/2; (vi) x, −y+1, −z+1; (vii) −x+1, y, −z+3/2. |
This report is the first example of an X-ray structural study of a pentaamminenitrosylchromium complex, [Cr(NO)(NH3)5]2+, even though complexes with X = Cl, Br, NO3, ClO4, B(C6H5)4 and OC6H2(NO2)3 have been characterized (Mori et al., 1963; Griffith et al., 1963; Kobayashi et al., 1969). The structure of related compound [Cr(NO)(H2O)5]SO4 (Ardon & Cohen, 1993) has been reported. The results of ab initio calculations on [Cr(NO)(H2O)5]2+ have also been reported (Shim et al., 1995).
The title compound, [Cr(NO)(NH3)5]Cl2 (Fig. 1 and Table 1), (I), was found to crystallize in the orthorhombic space group Cmcm with the Cr atom, the NO group and the N2 atom, trans to NO, having m2m symmetry imposing disorder in the N2H3 amine group. The remaining N atoms and the Cl atom are at sites with m symmetry.
The CrIII centre exists in a slightly distorted octahedral geometry with a strictly linear Cr—N—O arrangement (from symmetry). The N(nitrosyl)—Cr—N(ammonia, cis to NO) angles are 94.2 (1) and 92.8 (1)° so that the Cr—N(ammonia, cis to NO) bonds are slightly bent toward to the ammonia molecule in the trans position to NO.
The short Cr—N(nitrosyl) distance of 1.692 (7) Å indicates the presence of multiple bonding between these atoms. A short Cr—N(nitrosyl) distance of 1.682 (2) Å was also reported for [Cr(NO)(H2O)5]2+ (Ardon & Cohen, 1993). The Cr—N(ammonia) distances in [Cr(NH3)6]3+ are 2.070 (8) Å (Clegg et al., 1982) and 2.085 (10) Å (average; Dieterich & Stráhle, 1993). These are close to those of Cr—N(ammonia, cis to NO) in [Cr(NO)(NH3)5]2+.
The O(nitrosyl) atom appears to form hydrogen bonds with both H3 and H4 of adjacent ammonia molecules, with distances and angles as shown in Table 2.