Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103015014/jz1564sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103015014/jz1564Isup2.hkl |
CCDC reference: 221053
Compound (I) was prepared according to the method described by Pawson & Griffith (1975). Crystals were grown by adding a solution of [Bu4N][RuNCl4] in methanol to a solution of excess AsPh3 in acetone at room temperature and allowing slow evaporation of the solvent. The crystals are pronouncedly dichroic, namely red and yellow.
H atoms were found in a difference Fourier map and were included in the refinement at idealized positions, riding on their parent atom, with C—H bond lengths of 0.93 Å.
Ruthenium nitrido complexes have been well known since 1972 (Griffith & Pawson, 1972). However, all of the structurally characterized Ru≡N complexes with monodentate auxiliary ligands are square pyramidal and five-coordinate (Phillips & Skapski, 1975; Collison et al., 1981; Sharpley et al., 1988; Liang & Sharpley, 1996), which fact provides a qualitative indication of the strong trans-influence of the nitrido ligand. In order to obtain a good quantitative measure of the trans-influence unperturbed by the steric requirements of polydentate ligands, we have undertaken a study of mer-[RuNCl3(AsPh3)2] (I).
The structure of (I) consists of discrete monomers, and the coordination geometry (Fig. 1 and Table 1) of is distorted octahedral. The three chloride ligands are arranged in a meridional configuration in which one chloride ligand is trans to the nitride, as proposed by Pawson & Griffith (1975).
The Ru≡N bond length of 1.6161 (15) Å is relatively long compared with other ruthenium nitrido compounds and is only exceeded in bis(1,2-bezenedithiolate)nitridoruthenate(VI) [1.613 (5) and 1.621 (5) Å in two independent molecules; Sellmann et al., 1997] and µ-oxo-tetrakis(2,5-dimethyl-2,5-hexanediamine-N,N')nitridodiruthenium(VI) [1.66 (1) Å; Chiu et al., 1996].
The Ru—As bond length of 2.5533 (3) Å is the longest reported Ru—As bond length in ruthenium compounds with AsPh3 and related ligands. Note that arsine ligands support ruthenium in oxidation states varying from Ru0 in [Ru(AsPh3)(CO)4] (Martin et al., 1983) to RuVI in ruthenium nitride complexes such as the title compound.
In five- and six-coordinate complexes with strong π-donor ligands, such as oxide and nitride ligands, the central metal is invariably displaced out of the plane of the equatorial ligands, towards the multiply bonded ligand. This phenomenon is much less pronounced in the six-coordinate compounds, probably as a result of steric interactions. Given the N—Ru—Cl1 and N—Ru—As angles of 93.325 (7) and 93.59 (1)° in (I), the Ru atom lies 0.1483 (2) Å above the equatorial plane defined by? the two Cl and two As atoms. This deviation is less than half the out-of-plane distances seen in five-coordinate nitrido compounds, where the deviations range from 0.34 Å in [MoN(N3)4]- (Dehnicke et al., 1980) to 0.768 Å in [TcN(Se2C═C(CN)2)]2- (Abram et al., 1991). In (I), the Ru—Cltrans bond length [2.5020 (4) Å] is longer than the Ru—Clcis bond length [2.3786 (3) Å]. This trans influence is relatively small compared with that observed for other six-coordinate nitrido complexes (cf. Table 2), possibly because of the small out-of-plane displacement of the Ru atom in (I), which reflects the steric bulk of the AsPh3 ligands and the concomitant strain involved in closing all angles involving the arsine ligands.
The closely related compound mer-[Ru(NO)Cl3(AsPh3)2] (Souza et al., 1995) is isostructual with (I). The geometric parameters of these two complexes are almost identical (Table 3), but the nitrosyl ligand does not exert any trans influence. This result is parallelled for first-row transition metals by the strong trans influence found in [Mn(N)(CN)5]3- [0.253 (7) Å; Bendix et al., 2000] and the absence of any trans influence in [Mn(NO)(CN)5]3- [0.03 (1) Å; Tullberg and Vannerberg, 1967). These findings reflect the general rule that, while strong π-donor ligands exert a trans influence, π-acceptors do not (Lyne & Mingos, 1995).
Importantly, the steric demands of the AsPh3 ligand shield the nitrido ligand in (I) from intermolecular interactions. Accordingly, the packing (Fig. 2) is governed by the arrangement of the phenyl groups of the AsPh3 ligands, with several relatively short intermolecular C···C distances [3.696–3.9 Å]. The rhombicity of the molecules is mirrored in the packing; all Ru≡N directions are parallel (or antiparallel) and all As—As vectors are parallel. The packing thus explains the strong dichroism of the solid compound and makes it a good candidate for polarized single-crystal absorption and luminescence spectroscopy (Cowman et al., 1976; Lamet et al., 1993) on an unperturbed Ru≡N moiety.
Data collection: COLLECT (Nonius, 1999); cell refinement: DIRAX (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997) and SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976).
[RuCl3N(AsC18H15)2] | F(000) = 1656 |
Mr = 833.87 | Dx = 1.713 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 34589 reflections |
a = 12.0020 (4) Å | θ = 2.2–35.0° |
b = 14.5630 (9) Å | µ = 2.79 mm−1 |
c = 18.526 (2) Å | T = 122 K |
β = 92.882 (5)° | Prism, red and yellow |
V = 3234.0 (4) Å3 | 0.27 × 0.18 × 0.14 mm |
Z = 4 |
Nonius KappaCCD area-detector diffractometer | 7120 independent reflections |
Radiation source: fine-focus sealed tube | 6361 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.045 |
ω and φ scans | θmax = 35.0°, θmin = 2.2° |
Absorption correction: integration Gaussian integration (Coppens, 1970) | h = −19→19 |
Tmin = 0.462, Tmax = 0.877 | k = −23→23 |
55021 measured reflections | l = −29→29 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.022 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.052 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0173P)2 + 4.8314P] where P = (Fo2 + 2Fc2)/3 |
7120 reflections | (Δ/σ)max = 0.001 |
196 parameters | Δρmax = 0.62 e Å−3 |
0 restraints | Δρmin = −0.93 e Å−3 |
[RuCl3N(AsC18H15)2] | V = 3234.0 (4) Å3 |
Mr = 833.87 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 12.0020 (4) Å | µ = 2.79 mm−1 |
b = 14.5630 (9) Å | T = 122 K |
c = 18.526 (2) Å | 0.27 × 0.18 × 0.14 mm |
β = 92.882 (5)° |
Nonius KappaCCD area-detector diffractometer | 7120 independent reflections |
Absorption correction: integration Gaussian integration (Coppens, 1970) | 6361 reflections with I > 2σ(I) |
Tmin = 0.462, Tmax = 0.877 | Rint = 0.045 |
55021 measured reflections |
R[F2 > 2σ(F2)] = 0.022 | 0 restraints |
wR(F2) = 0.052 | H-atom parameters constrained |
S = 1.09 | Δρmax = 0.62 e Å−3 |
7120 reflections | Δρmin = −0.93 e Å−3 |
196 parameters |
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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) - 0.0706 (0.0010) x + 14.5627 (0.0017) y + 0.0370 (0.0005) z = 3.8768 (0.0005) * 0.0000 (0.0000) As1 * 0.0000 (0.0000) Cl1 * 0.0000 (0.0000) As1 * 0.0000 (0.0000) Cl1 - 0.1483 (0.0002) Ru1 Rms deviation of fitted atoms = 0.0000 |
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. |
x | y | z | Uiso*/Ueq | ||
Ru1 | 0.0000 | 0.255394 (8) | 0.2500 | 0.00929 (3) | |
N1 | 0.0000 | 0.14442 (10) | 0.2500 | 0.0153 (3) | |
Cl1 | −0.17848 (2) | 0.26487 (2) | 0.188570 (16) | 0.01445 (5) | |
Cl2 | 0.0000 | 0.42720 (3) | 0.2500 | 0.01609 (7) | |
As1 | 0.106252 (9) | 0.266385 (8) | 0.134322 (6) | 0.00948 (3) | |
C1 | 0.15328 (9) | 0.14305 (8) | 0.11152 (6) | 0.01168 (18) | |
C2 | 0.21054 (10) | 0.09280 (8) | 0.16602 (7) | 0.0142 (2) | |
H2 | 0.2264 | 0.1193 | 0.2110 | 0.017* | |
C3 | 0.24374 (11) | 0.00301 (8) | 0.15278 (7) | 0.0164 (2) | |
H3 | 0.2830 | −0.0302 | 0.1886 | 0.020* | |
C4 | 0.21818 (11) | −0.03692 (9) | 0.08593 (7) | 0.0183 (2) | |
H4 | 0.2406 | −0.0968 | 0.0771 | 0.022* | |
C5 | 0.15925 (12) | 0.01222 (9) | 0.03225 (7) | 0.0182 (2) | |
H5 | 0.1410 | −0.0154 | −0.0120 | 0.022* | |
C6 | 0.12729 (11) | 0.10298 (8) | 0.04445 (7) | 0.0149 (2) | |
H6 | 0.0891 | 0.1363 | 0.0082 | 0.018* | |
C7 | 0.02819 (9) | 0.30835 (8) | 0.04667 (6) | 0.01176 (18) | |
C8 | −0.07042 (10) | 0.26370 (8) | 0.02368 (7) | 0.0146 (2) | |
H8 | −0.0995 | 0.2174 | 0.0518 | 0.017* | |
C9 | −0.12484 (10) | 0.28882 (9) | −0.04138 (7) | 0.0166 (2) | |
H9 | −0.1902 | 0.2590 | −0.0569 | 0.020* | |
C10 | −0.08192 (11) | 0.35828 (9) | −0.08324 (7) | 0.0177 (2) | |
H10 | −0.1185 | 0.3747 | −0.1268 | 0.021* | |
C11 | 0.01552 (11) | 0.40321 (9) | −0.06015 (7) | 0.0179 (2) | |
H11 | 0.0437 | 0.4501 | −0.0880 | 0.021* | |
C12 | 0.07109 (10) | 0.37821 (8) | 0.00478 (7) | 0.0148 (2) | |
H12 | 0.1366 | 0.4081 | 0.0201 | 0.018* | |
C13 | 0.24129 (9) | 0.33844 (8) | 0.14375 (6) | 0.01186 (18) | |
C14 | 0.34570 (10) | 0.29664 (8) | 0.14436 (7) | 0.0156 (2) | |
H14 | 0.3514 | 0.2334 | 0.1386 | 0.019* | |
C15 | 0.44156 (11) | 0.35006 (10) | 0.15365 (8) | 0.0192 (2) | |
H15 | 0.5114 | 0.3222 | 0.1546 | 0.023* | |
C16 | 0.43369 (11) | 0.44470 (9) | 0.16155 (7) | 0.0181 (2) | |
H16 | 0.4980 | 0.4801 | 0.1675 | 0.022* | |
C17 | 0.32932 (11) | 0.48636 (9) | 0.16057 (7) | 0.0163 (2) | |
H17 | 0.3239 | 0.5497 | 0.1656 | 0.020* | |
C18 | 0.23283 (10) | 0.43345 (8) | 0.15209 (7) | 0.0144 (2) | |
H18 | 0.1631 | 0.4613 | 0.1520 | 0.017* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ru1 | 0.00894 (5) | 0.00864 (5) | 0.01011 (5) | 0.000 | −0.00124 (4) | 0.000 |
N1 | 0.0158 (6) | 0.0132 (6) | 0.0170 (7) | 0.000 | 0.0000 (5) | 0.000 |
Cl1 | 0.01121 (11) | 0.01749 (12) | 0.01422 (12) | −0.00021 (8) | −0.00373 (9) | 0.00074 (9) |
Cl2 | 0.01383 (16) | 0.01050 (15) | 0.0239 (2) | 0.000 | 0.00106 (14) | 0.000 |
As1 | 0.00927 (5) | 0.00871 (5) | 0.01031 (5) | −0.00031 (3) | −0.00109 (4) | 0.00038 (3) |
C1 | 0.0116 (4) | 0.0106 (4) | 0.0128 (5) | 0.0003 (3) | 0.0001 (4) | 0.0003 (3) |
C2 | 0.0154 (5) | 0.0130 (5) | 0.0138 (5) | 0.0018 (4) | −0.0017 (4) | 0.0001 (4) |
C3 | 0.0170 (5) | 0.0135 (5) | 0.0185 (5) | 0.0037 (4) | −0.0005 (4) | 0.0015 (4) |
C4 | 0.0224 (6) | 0.0121 (5) | 0.0205 (6) | 0.0024 (4) | 0.0035 (5) | −0.0008 (4) |
C5 | 0.0260 (6) | 0.0141 (5) | 0.0146 (5) | 0.0011 (4) | 0.0014 (5) | −0.0034 (4) |
C6 | 0.0190 (5) | 0.0132 (5) | 0.0124 (5) | 0.0009 (4) | 0.0000 (4) | −0.0003 (4) |
C7 | 0.0112 (4) | 0.0121 (4) | 0.0118 (5) | 0.0010 (3) | −0.0011 (4) | 0.0003 (3) |
C8 | 0.0129 (5) | 0.0156 (5) | 0.0151 (5) | −0.0018 (4) | −0.0014 (4) | 0.0006 (4) |
C9 | 0.0141 (5) | 0.0189 (5) | 0.0164 (5) | 0.0005 (4) | −0.0038 (4) | −0.0019 (4) |
C10 | 0.0194 (6) | 0.0181 (5) | 0.0151 (5) | 0.0045 (4) | −0.0040 (4) | 0.0010 (4) |
C11 | 0.0209 (6) | 0.0158 (5) | 0.0167 (5) | 0.0012 (4) | −0.0011 (4) | 0.0043 (4) |
C12 | 0.0142 (5) | 0.0145 (5) | 0.0156 (5) | −0.0008 (4) | −0.0016 (4) | 0.0019 (4) |
C13 | 0.0111 (4) | 0.0126 (4) | 0.0118 (5) | −0.0024 (3) | −0.0007 (4) | −0.0005 (4) |
C14 | 0.0123 (5) | 0.0150 (5) | 0.0194 (5) | −0.0002 (4) | 0.0005 (4) | −0.0022 (4) |
C15 | 0.0107 (5) | 0.0231 (6) | 0.0237 (6) | −0.0013 (4) | 0.0000 (4) | −0.0036 (5) |
C16 | 0.0152 (5) | 0.0215 (6) | 0.0175 (5) | −0.0063 (4) | 0.0010 (4) | −0.0043 (4) |
C17 | 0.0180 (5) | 0.0144 (5) | 0.0165 (5) | −0.0045 (4) | 0.0017 (4) | −0.0027 (4) |
C18 | 0.0135 (5) | 0.0135 (5) | 0.0162 (5) | −0.0012 (4) | 0.0009 (4) | −0.0005 (4) |
Ru1—N1 | 1.6161 (15) | C7—C8 | 1.3979 (16) |
Ru1—As1 | 2.5533 (3) | C8—C9 | 1.3906 (17) |
Ru1—Cl1 | 2.3786 (3) | C8—H8 | 0.9300 |
Ru1—Cl1i | 2.3786 (3) | C9—C10 | 1.3893 (19) |
Ru1—Cl2 | 2.5020 (4) | C9—H9 | 0.9300 |
Ru1—As1i | 2.5533 (3) | C10—C11 | 1.3887 (19) |
As1—C13 | 1.9313 (11) | C10—H10 | 0.9300 |
As1—C7 | 1.9327 (11) | C11—C12 | 1.3942 (18) |
As1—C1 | 1.9357 (11) | C11—H11 | 0.9300 |
C1—C6 | 1.3938 (17) | C12—H12 | 0.9300 |
C1—C2 | 1.3991 (16) | C13—C14 | 1.3927 (17) |
C2—C3 | 1.3924 (17) | C13—C18 | 1.3965 (16) |
C2—H2 | 0.9300 | C14—C15 | 1.3924 (18) |
C3—C4 | 1.3884 (19) | C14—H14 | 0.9300 |
C3—H3 | 0.9300 | C15—C16 | 1.3898 (19) |
C4—C5 | 1.3896 (19) | C15—H15 | 0.9300 |
C4—H4 | 0.9300 | C16—C17 | 1.3911 (19) |
C5—C6 | 1.3979 (17) | C16—H16 | 0.9300 |
C5—H5 | 0.9300 | C17—C18 | 1.3932 (17) |
C6—H6 | 0.9300 | C17—H17 | 0.9300 |
C7—C12 | 1.3937 (17) | C18—H18 | 0.9300 |
N1—Ru1—Cl1 | 93.325 (7) | C5—C6—H6 | 120.4 |
N1—Ru1—Cl1i | 93.324 (7) | C12—C7—C8 | 120.04 (11) |
Cl1—Ru1—Cl1i | 173.350 (15) | C12—C7—As1 | 121.44 (9) |
N1—Ru1—Cl2 | 180.0 | C8—C7—As1 | 118.44 (9) |
Cl1—Ru1—Cl2 | 86.675 (7) | C9—C8—C7 | 119.69 (11) |
Cl1i—Ru1—Cl2 | 86.676 (7) | C9—C8—H8 | 120.2 |
N1—Ru1—As1 | 93.59 (1) | C7—C8—H8 | 120.2 |
Cl1—Ru1—As1 | 94.047 (8) | C10—C9—C8 | 120.28 (12) |
Cl1i—Ru1—As1 | 85.537 (8) | C10—C9—H9 | 119.9 |
Cl2—Ru1—As1 | 86.41 (1) | C8—C9—H9 | 119.9 |
N1—Ru1—As1i | 93.59 (1) | C11—C10—C9 | 120.07 (12) |
Cl1—Ru1—As1i | 85.535 (8) | C11—C10—H10 | 120.0 |
Cl1i—Ru1—As1i | 94.046 (8) | C9—C10—H10 | 120.0 |
Cl2—Ru1—As1i | 86.41 (1) | C10—C11—C12 | 120.12 (12) |
As1—Ru1—As1i | 172.812 (7) | C10—C11—H11 | 119.9 |
C13—As1—C7 | 105.86 (5) | C12—C11—H11 | 119.9 |
C13—As1—C1 | 105.74 (5) | C7—C12—C11 | 119.79 (11) |
C7—As1—C1 | 104.15 (5) | C7—C12—H12 | 120.1 |
C13—As1—Ru1 | 114.23 (3) | C11—C12—H12 | 120.1 |
C7—As1—Ru1 | 118.92 (3) | C14—C13—C18 | 120.17 (11) |
C1—As1—Ru1 | 106.76 (4) | C14—C13—As1 | 120.92 (9) |
C6—C1—C2 | 120.28 (11) | C18—C13—As1 | 118.88 (9) |
C6—C1—As1 | 121.90 (9) | C15—C14—C13 | 119.63 (11) |
C2—C1—As1 | 117.76 (9) | C15—C14—H14 | 120.2 |
C3—C2—C1 | 119.91 (11) | C13—C14—H14 | 120.2 |
C3—C2—H2 | 120.0 | C16—C15—C14 | 120.46 (12) |
C1—C2—H2 | 120.0 | C16—C15—H15 | 119.8 |
C4—C3—C2 | 119.87 (12) | C14—C15—H15 | 119.8 |
C4—C3—H3 | 120.1 | C15—C16—C17 | 119.80 (12) |
C2—C3—H3 | 120.1 | C15—C16—H16 | 120.1 |
C3—C4—C5 | 120.30 (11) | C17—C16—H16 | 120.1 |
C3—C4—H4 | 119.9 | C16—C17—C18 | 120.21 (12) |
C5—C4—H4 | 119.9 | C16—C17—H17 | 119.9 |
C4—C5—C6 | 120.33 (12) | C18—C17—H17 | 119.9 |
C4—C5—H5 | 119.8 | C17—C18—C13 | 119.72 (11) |
C6—C5—H5 | 119.8 | C17—C18—H18 | 120.1 |
C1—C6—C5 | 119.29 (11) | C13—C18—H18 | 120.1 |
C1—C6—H6 | 120.4 |
Symmetry code: (i) −x, y, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [RuCl3N(AsC18H15)2] |
Mr | 833.87 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 122 |
a, b, c (Å) | 12.0020 (4), 14.5630 (9), 18.526 (2) |
β (°) | 92.882 (5) |
V (Å3) | 3234.0 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.79 |
Crystal size (mm) | 0.27 × 0.18 × 0.14 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector |
Absorption correction | Integration Gaussian integration (Coppens, 1970) |
Tmin, Tmax | 0.462, 0.877 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 55021, 7120, 6361 |
Rint | 0.045 |
(sin θ/λ)max (Å−1) | 0.806 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.022, 0.052, 1.09 |
No. of reflections | 7120 |
No. of parameters | 196 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.62, −0.93 |
Computer programs: COLLECT (Nonius, 1999), DIRAX (Duisenberg, 1992), EVALCCD (Duisenberg, 1998), SHELXS97 (Sheldrick, 1997) and SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976).
Ru1—N1 | 1.6161 (15) | Ru1—Cl1 | 2.3786 (3) |
Ru1—As1 | 2.5533 (3) | Ru1—Cl2 | 2.5020 (4) |
N1—Ru1—Cl1 | 93.325 (7) | N1—Ru1—As1 | 93.59 (1) |
Cl1—Ru1—Cl1i | 173.350 (15) | Cl1—Ru1—As1 | 94.047 (8) |
N1—Ru1—Cl2 | 180.0 | Cl2—Ru1—As1 | 86.41 (1) |
Cl1—Ru1—Cl2 | 86.675 (7) | As1—Ru1—As1i | 172.812 (7) |
Symmetry code: (i) −x, y, −z+1/2. |
Complex | Average | |||
M≡N | M—Xtrans | M—Xcis | N≡M—Leq | |
mer-[RuNCl3(AsPh3)2] a | ||||
1.6161 (15) | 2.5020 (4) | 2.3786 (3) | 93.325 (7)-93.59 (1) | |
fac-[OsNCl3(dpae)] b | ||||
1.68 (2) | 2.507 (5) | 2.377 (5) | 86.5 (5)-102.6 (5) | |
[OsNCl5]2- c | ||||
1.614 (13) | 2.605 (4) | 2.363 (4) | 95.44 (6)-97.5 (5) | |
[OsN(CN)5]2- d | ||||
1.647 (7) | 2.353 (8) | 2.080 (8) | 93.3 (3)-99.4 (3) | |
[ReN(NCS)5]2- e | ||||
1.657 (12) | 2.307 (12) | 2.023 (8) | 95.5 (4)-96.8 (5) | |
mer-[ReNBr2(PMe2Ph)3] f | ||||
1.667 (6) | 2.795 (1) | 2.587 (1) | 91.0 (2)-103.6 (2) |
Notes: (a) present work; (b) Lam et al. (1993) [dpae is bis(diphenylarsino)ethane]; (c) Bright & Ibers (1969); (d) Che et al. (1989); (e) Carrondo et al. (1978); (f) Schmidt-Brücken & Abram (2001); |
mer-[RuNCl3(AsPh3)2] | mer-[Ru(NO)Cl3(AsPh3)2] | |
Ru—N | 1.6161 (15) | 1.729 (7) |
Ru—Clcis | 2.3786 (3) | 2.384 (1) |
Ru—Cltrans | 2.5020 (4) | 2.346 (2) |
N—Ru—Clcis | 93.325 (7) | 90.0 (1) |
N—Ru—As | 93.59 (1) | 91.5 (1) |
Ruthenium nitrido complexes have been well known since 1972 (Griffith & Pawson, 1972). However, all of the structurally characterized Ru≡N complexes with monodentate auxiliary ligands are square pyramidal and five-coordinate (Phillips & Skapski, 1975; Collison et al., 1981; Sharpley et al., 1988; Liang & Sharpley, 1996), which fact provides a qualitative indication of the strong trans-influence of the nitrido ligand. In order to obtain a good quantitative measure of the trans-influence unperturbed by the steric requirements of polydentate ligands, we have undertaken a study of mer-[RuNCl3(AsPh3)2] (I).
The structure of (I) consists of discrete monomers, and the coordination geometry (Fig. 1 and Table 1) of is distorted octahedral. The three chloride ligands are arranged in a meridional configuration in which one chloride ligand is trans to the nitride, as proposed by Pawson & Griffith (1975).
The Ru≡N bond length of 1.6161 (15) Å is relatively long compared with other ruthenium nitrido compounds and is only exceeded in bis(1,2-bezenedithiolate)nitridoruthenate(VI) [1.613 (5) and 1.621 (5) Å in two independent molecules; Sellmann et al., 1997] and µ-oxo-tetrakis(2,5-dimethyl-2,5-hexanediamine-N,N')nitridodiruthenium(VI) [1.66 (1) Å; Chiu et al., 1996].
The Ru—As bond length of 2.5533 (3) Å is the longest reported Ru—As bond length in ruthenium compounds with AsPh3 and related ligands. Note that arsine ligands support ruthenium in oxidation states varying from Ru0 in [Ru(AsPh3)(CO)4] (Martin et al., 1983) to RuVI in ruthenium nitride complexes such as the title compound.
In five- and six-coordinate complexes with strong π-donor ligands, such as oxide and nitride ligands, the central metal is invariably displaced out of the plane of the equatorial ligands, towards the multiply bonded ligand. This phenomenon is much less pronounced in the six-coordinate compounds, probably as a result of steric interactions. Given the N—Ru—Cl1 and N—Ru—As angles of 93.325 (7) and 93.59 (1)° in (I), the Ru atom lies 0.1483 (2) Å above the equatorial plane defined by? the two Cl and two As atoms. This deviation is less than half the out-of-plane distances seen in five-coordinate nitrido compounds, where the deviations range from 0.34 Å in [MoN(N3)4]- (Dehnicke et al., 1980) to 0.768 Å in [TcN(Se2C═C(CN)2)]2- (Abram et al., 1991). In (I), the Ru—Cltrans bond length [2.5020 (4) Å] is longer than the Ru—Clcis bond length [2.3786 (3) Å]. This trans influence is relatively small compared with that observed for other six-coordinate nitrido complexes (cf. Table 2), possibly because of the small out-of-plane displacement of the Ru atom in (I), which reflects the steric bulk of the AsPh3 ligands and the concomitant strain involved in closing all angles involving the arsine ligands.
The closely related compound mer-[Ru(NO)Cl3(AsPh3)2] (Souza et al., 1995) is isostructual with (I). The geometric parameters of these two complexes are almost identical (Table 3), but the nitrosyl ligand does not exert any trans influence. This result is parallelled for first-row transition metals by the strong trans influence found in [Mn(N)(CN)5]3- [0.253 (7) Å; Bendix et al., 2000] and the absence of any trans influence in [Mn(NO)(CN)5]3- [0.03 (1) Å; Tullberg and Vannerberg, 1967). These findings reflect the general rule that, while strong π-donor ligands exert a trans influence, π-acceptors do not (Lyne & Mingos, 1995).
Importantly, the steric demands of the AsPh3 ligand shield the nitrido ligand in (I) from intermolecular interactions. Accordingly, the packing (Fig. 2) is governed by the arrangement of the phenyl groups of the AsPh3 ligands, with several relatively short intermolecular C···C distances [3.696–3.9 Å]. The rhombicity of the molecules is mirrored in the packing; all Ru≡N directions are parallel (or antiparallel) and all As—As vectors are parallel. The packing thus explains the strong dichroism of the solid compound and makes it a good candidate for polarized single-crystal absorption and luminescence spectroscopy (Cowman et al., 1976; Lamet et al., 1993) on an unperturbed Ru≡N moiety.