Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270108005970/sf3073sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270108005970/sf3073Isup2.hkl |
CCDC reference: 686417
Crystals of (I) were prepared by mixing a 0.1 M aqueous solution of Cu(BF4)2 (5 ml) with a 0.1 M methanolic solution of phen (10 ml). To the resulting green solution, a 0.1 M aqueous solution of NaN(CN)2 (5 ml) was added (all solutions were warmed before mixing). Green crystals of the title complex appeared after 3 d. The crystals were filtered off and dried in air.
All H-atom positions were calculated using the appropriate riding model, with C—H = and with Uiso(H) = 1.2Ueq(C). The maximum and minimum residual electron-density peaks are located 0.97 and 0.93 Å from the Cu atom, respectively.
Understanding the shape of coordination polyhedra (SCP) in the case of five-coordination is one of the current problems in coordination chemistry (Murphy & Hathaway, 2003). The molecular structures of five-coordinated copper(II) complexes range from regular trigonal–bipyramidal to regular tetragonal–pyramidal, with most complexes falling between these two stereochemistries. In the majority of [CuX(L)2]Y complexes, where L are bidentate chelate bonded ligands and X and Y are anions of charge -1, the differences in stereochemistry may be associated with the differences in the ligands present (Youngme et al., 2007). A number of different structural approaches have been used in the past to describe the geometries of these compounds (Potočňák, Dunaj-Jurčo, Mikloš & Jäger, 2001, and references therein). In our search for possible reasons for different SCP in related compounds, we have previously studied the structures of five-coordinated copper(II) coordination compounds of the general formula [Cu(dca)(L)2]Y, where L is a bidentate chelate ligand 1,10-phenanthroline (phen) or 2,2'-bipyridine (bpy), dca is the dicyanamide anion, N(CN)2-, and Y is an anion of charge -1 (Potočňák et al., 2005). The SCP in these compounds is more or less distorted trigonal bipyramidal. However, we have found that the SCP is more distorted in compounds with bpy molecules than in those involving phen molecules. We suppose that the reason could be the different rigidity between highly rigid phen and less rigid bpy ligands. The title compound, [Cu(dca)(phen)2]BF4, (I), has been prepared as the next example within the framework of our ongoing studies. We present here the structure of (I) and compare it with the previously reported compound [Cu(dca)(bpy)2]BF4, (II) (Potočňák, Dunaj-Jurčo, Mikloš, Massa & Jäger, 2001).
Fig. 1 shows the structure and labelling scheme of one formula unit of (I). The Cu atom is coordinated by two chelate-like bound phen molecules in two axial [average Cu—N = 1.998 (3) Å] and two equatorial positions [average Cu—N = 2.09 (6) Å], whereas one terminal N atom of the dca ligand occupies the third equatorial position of a deformed trigonal bipyramid [Cu—N1 = 1.996 (2) Å]. The BF4- anion does not enter the inner coordination sphere. The same coordination of bpy and dca ligands and similar corresponding bond distances were also observed in (II).
Although the SCP around the Cu atoms in (I) and (II) are quite similar, they still differ in some details. The out-of-plane angles in (I) lie within the range 80.29 (9)–97.52 (9)°, similar to those observed in (II). The bond angles in the equatorial planes of (I) and (II) differ considerably from the ideal trigonal angle of 120°. If, according to the criteria of Harrison & Hathaway (1980), the angles N1—Cu—N20, N1—Cu—N40 and N20—Cu—N40 are labelled α1, α2 and α3, respectively, then the small angle α3 [109.41 (9)°], which is opposite to the Cu—N1 bond (N1 from the dca), and the rather large difference of 22.67° between α1 and α2, classify the coordination polyhedron around the Cu atom in (I) as trigonal bipyramidal, with a distortion towards square pyramidal. Atoms N10, N30 and N40 of the phen ligands and atom N1 of the dca represent the base of the distorted square pyramid thus formed [average Cu—N = 2.01 (3) Å], whereas atom N20, owing to the Jahn–Teller effect, occupies the axial position at a longer distance [2.134 (2) Å]. The same result can be obtained, of course, when using the τ parameter of Addison et al. (1984) as the criterion, which is 67.7 here (the τ parameter is 100 for an ideal trigonal bipyramid and 0 for an ideal square pyramid). For (II), the smaller value of the α3 angle [106.44 (11)°], and the larger difference of 36.45° between α1 and α2, indicate a greater distortion of the trigonal bipyramid towards a squre pyramid compared with (I). The smaller value of the τ parameter (54.2) confirms this increasing distortion. This may be seen as a confirmation of our hypothesis on the dependence of the SCP on the different rigidity of the chelate L ligands employed.
There are three canonical formulae describing the bonding mode in a dicyanamide ligand (Golub et al., 1986). Inspection of the bond lengths (Table 1) shows that the bonds associated with atom C1 are a little shorter than the bonds around atom C2. Nevertheless, both Ncyano≡C (C1≡ N1 and C2≡ N2) bond lengths in (I) are normal for an N≡C triple bond. On the other hand, the C2—N3 bond length is only slightly shorter than a single bond between an N atom and an sp-hybridized C atom [Standard value and reference?], whereas the C1—N3 bond length is only slightly longer than a double bond between an N atom and an sp-hybridized C atom [Standard value and reference?]. Therefore, no canonical formula correctly describes the bonding mode in the dicyanamide ligand in (I). In accordance with Golub et al. (1986), the bonding mode of the dicyanamide to the Cu atom can be considered as angular [C1—N1—Cu = 144.2 (2)°].
The BF4- anion remains uncoordinated, with B—F bond lengths and F—B—F angles typical for tetrafluoroborates (Cambridge Structural Database, Version? How many hits?; Allen, 2002). The anion is involved in numerous weak C—H···F hydrogen bonds which contribute to the stabilization of the crystal structure of (I). Those with a C—H···F angle greater than 120° and an H···F distance less than 2.6 Å are given in Table 2. Through these hydrogen bonds, cations and anions are interconnected to form layers along the (001) plane, as shown in Fig. 2.
Further stabilization of the structure may come from possible face-to-face π–π interactions between stacked phen molecules. There is a stacking interaction involving one phenyl and one pyridine ring of the phen ligands from neighbouring layers [that containing atoms N30 and N40 and its symmetry related layer at (1 - x, 1 - y, 1 - z)], with a centroid-to-centroid distance of 3.609 (4) Å. Another stacking interaction involves only the phenyl rings of the phen ligands from the same layer containing atoms N10 and N20 and its symmetry related layer at (1 - x, 1 - y, -z), with a centroid-to-centroid distance of 3.498 (4) Å.
For related literature, see: Addison et al. (1984); Allen (2002); Golub et al. (1986); Harrison & Hathaway (1980); Murphy & Hathaway (2003); Potočňák et al. (2005); Potočňák, Dunaj-Jurčo, Mikloš & Jäger (2001); Potočňák, Dunaj-Jurčo, Mikloš, Massa & Jäger (2001); Youngme et al. (2007).
Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: PARST (Nardelli, 1983) and SHELXL97 (Sheldrick, 2008).
[Cu(C2N3)(C12H8N2)2]BF4 | Z = 2 |
Mr = 576.81 | F(000) = 582 |
Triclinic, P1 | Dx = 1.625 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.0601 (8) Å | Cell parameters from 6660 reflections |
b = 9.2246 (9) Å | θ = 2.6–31.7° |
c = 16.4286 (15) Å | µ = 0.99 mm−1 |
α = 92.344 (7)° | T = 110 K |
β = 96.656 (8)° | Prism, blue |
γ = 103.097 (8)° | 0.40 × 0.35 × 0.30 mm |
V = 1178.8 (2) Å3 |
Oxford Diffraction MODEL? CCD diffractometer | 4116 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 3555 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
Detector resolution: 8.3611 pixels mm-1 | θmax = 25.0°, θmin = 2.6° |
Rotation method data acquisition using ω scans | h = −8→9 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007) | k = −10→10 |
Tmin = 0.693, Tmax = 0.755 | l = −19→18 |
8578 measured reflections |
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)] = 0.041 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.119 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0901P)2 + 0.3012P] where P = (Fo2 + 2Fc2)/3 |
4116 reflections | (Δ/σ)max < 0.001 |
352 parameters | Δρmax = 0.98 e Å−3 |
0 restraints | Δρmin = −0.40 e Å−3 |
[Cu(C2N3)(C12H8N2)2]BF4 | γ = 103.097 (8)° |
Mr = 576.81 | V = 1178.8 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.0601 (8) Å | Mo Kα radiation |
b = 9.2246 (9) Å | µ = 0.99 mm−1 |
c = 16.4286 (15) Å | T = 110 K |
α = 92.344 (7)° | 0.40 × 0.35 × 0.30 mm |
β = 96.656 (8)° |
Oxford Diffraction MODEL? CCD diffractometer | 4116 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007) | 3555 reflections with I > 2σ(I) |
Tmin = 0.693, Tmax = 0.755 | Rint = 0.022 |
8578 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.119 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.98 e Å−3 |
4116 reflections | Δρmin = −0.40 e Å−3 |
352 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. |
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 | ||
Cu1 | 0.53373 (4) | 0.42489 (4) | 0.255605 (19) | 0.01979 (14) | |
C1 | 0.1535 (4) | 0.3993 (3) | 0.22133 (16) | 0.0218 (6) | |
C2 | −0.0715 (4) | 0.2322 (4) | 0.15261 (19) | 0.0279 (7) | |
N1 | 0.2962 (3) | 0.4577 (3) | 0.23778 (15) | 0.0268 (6) | |
N2 | −0.1389 (4) | 0.1325 (3) | 0.10656 (19) | 0.0434 (7) | |
N3 | −0.0102 (3) | 0.3475 (3) | 0.20629 (17) | 0.0325 (6) | |
N10 | 0.4887 (3) | 0.3019 (3) | 0.14893 (14) | 0.0218 (5) | |
N20 | 0.7108 (3) | 0.5639 (3) | 0.18836 (14) | 0.0217 (5) | |
N30 | 0.5900 (3) | 0.5510 (2) | 0.36071 (14) | 0.0185 (5) | |
N40 | 0.6581 (3) | 0.2900 (2) | 0.32343 (14) | 0.0197 (5) | |
C11 | 0.5802 (3) | 0.3626 (3) | 0.08939 (16) | 0.0206 (6) | |
C12 | 0.3698 (4) | 0.1740 (3) | 0.12968 (19) | 0.0275 (7) | |
H12 | 0.3052 | 0.1305 | 0.1710 | 0.033* | |
C13 | 0.3380 (4) | 0.1030 (3) | 0.05143 (18) | 0.0288 (7) | |
H13 | 0.2523 | 0.0128 | 0.0397 | 0.035* | |
C14 | 0.4308 (4) | 0.1634 (3) | −0.00906 (18) | 0.0275 (7) | |
H14 | 0.4098 | 0.1156 | −0.0628 | 0.033* | |
C15 | 0.5572 (4) | 0.2969 (3) | 0.00945 (17) | 0.0246 (6) | |
C16 | 0.6637 (4) | 0.3676 (4) | −0.04881 (18) | 0.0287 (7) | |
H16 | 0.6507 | 0.3229 | −0.1030 | 0.034* | |
C21 | 0.7025 (3) | 0.5023 (3) | 0.11121 (17) | 0.0210 (6) | |
C22 | 0.8249 (4) | 0.6927 (3) | 0.20958 (19) | 0.0261 (6) | |
H22 | 0.8341 | 0.7364 | 0.2638 | 0.031* | |
C23 | 0.9316 (4) | 0.7662 (4) | 0.15555 (19) | 0.0323 (7) | |
H23 | 1.0112 | 0.8580 | 0.1731 | 0.039* | |
C24 | 0.9210 (4) | 0.7059 (4) | 0.0777 (2) | 0.0322 (7) | |
H24 | 0.9918 | 0.7559 | 0.0403 | 0.039* | |
C25 | 0.8043 (3) | 0.5688 (3) | 0.05290 (18) | 0.0260 (7) | |
C26 | 0.7822 (4) | 0.4967 (4) | −0.02750 (19) | 0.0305 (7) | |
H26 | 0.8523 | 0.5405 | −0.0668 | 0.037* | |
C31 | 0.6781 (3) | 0.4922 (3) | 0.42110 (16) | 0.0180 (6) | |
C32 | 0.5504 (3) | 0.6805 (3) | 0.37700 (18) | 0.0222 (6) | |
H32 | 0.4873 | 0.7212 | 0.3350 | 0.027* | |
C33 | 0.5985 (3) | 0.7586 (3) | 0.45389 (18) | 0.0229 (6) | |
H33 | 0.5696 | 0.8516 | 0.4634 | 0.028* | |
C34 | 0.6877 (3) | 0.7006 (3) | 0.51559 (18) | 0.0227 (6) | |
H34 | 0.7207 | 0.7528 | 0.5681 | 0.027* | |
C35 | 0.7299 (3) | 0.5627 (3) | 0.50017 (17) | 0.0205 (6) | |
C36 | 0.8182 (3) | 0.4895 (3) | 0.56035 (17) | 0.0236 (6) | |
H36 | 0.8536 | 0.5355 | 0.6143 | 0.028* | |
C41 | 0.7142 (3) | 0.3509 (3) | 0.40137 (17) | 0.0184 (6) | |
C42 | 0.6930 (4) | 0.1610 (3) | 0.30299 (19) | 0.0250 (6) | |
H42 | 0.6536 | 0.1169 | 0.2489 | 0.030* | |
C43 | 0.7853 (4) | 0.0871 (3) | 0.3575 (2) | 0.0291 (7) | |
H43 | 0.8116 | −0.0035 | 0.3398 | 0.035* | |
C44 | 0.8376 (4) | 0.1460 (3) | 0.4363 (2) | 0.0282 (7) | |
H44 | 0.8976 | 0.0950 | 0.4743 | 0.034* | |
C45 | 0.8023 (3) | 0.2827 (3) | 0.46114 (18) | 0.0216 (6) | |
C46 | 0.8524 (3) | 0.3553 (3) | 0.54158 (18) | 0.0254 (7) | |
H46 | 0.9107 | 0.3088 | 0.5827 | 0.030* | |
B1 | 0.2497 (4) | 0.9758 (4) | 0.3295 (2) | 0.0268 (7) | |
F1 | 0.2440 (2) | 1.1165 (2) | 0.30280 (11) | 0.0356 (4) | |
F2 | 0.3077 (2) | 0.8958 (2) | 0.26954 (12) | 0.0421 (5) | |
F3 | 0.0841 (2) | 0.9025 (2) | 0.34271 (12) | 0.0381 (5) | |
F4 | 0.3598 (2) | 0.9905 (2) | 0.40227 (11) | 0.0343 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0178 (2) | 0.0210 (2) | 0.0190 (2) | 0.00179 (14) | 0.00242 (13) | −0.00076 (14) |
C1 | 0.0263 (17) | 0.0257 (15) | 0.0157 (13) | 0.0092 (13) | 0.0064 (12) | 0.0020 (11) |
C2 | 0.0180 (14) | 0.0380 (18) | 0.0281 (16) | 0.0055 (13) | 0.0051 (13) | 0.0060 (15) |
N1 | 0.0201 (14) | 0.0339 (14) | 0.0246 (13) | 0.0046 (11) | 0.0006 (10) | −0.0046 (11) |
N2 | 0.0279 (15) | 0.0491 (18) | 0.0467 (18) | 0.0009 (13) | −0.0030 (13) | −0.0062 (15) |
N3 | 0.0171 (13) | 0.0361 (15) | 0.0427 (16) | 0.0032 (11) | 0.0072 (11) | −0.0066 (13) |
N10 | 0.0205 (12) | 0.0213 (12) | 0.0229 (12) | 0.0031 (10) | 0.0034 (10) | 0.0017 (10) |
N20 | 0.0171 (12) | 0.0246 (12) | 0.0230 (13) | 0.0034 (10) | 0.0033 (9) | 0.0017 (10) |
N30 | 0.0130 (11) | 0.0187 (12) | 0.0227 (12) | 0.0015 (9) | 0.0022 (9) | 0.0019 (9) |
N40 | 0.0144 (11) | 0.0208 (12) | 0.0230 (12) | 0.0003 (9) | 0.0060 (9) | 0.0013 (10) |
C11 | 0.0187 (14) | 0.0273 (15) | 0.0186 (14) | 0.0112 (12) | 0.0020 (11) | 0.0022 (12) |
C12 | 0.0285 (16) | 0.0244 (15) | 0.0268 (16) | 0.0006 (12) | 0.0032 (12) | −0.0005 (12) |
C13 | 0.0307 (16) | 0.0251 (16) | 0.0276 (16) | 0.0027 (13) | 0.0006 (13) | −0.0047 (13) |
C14 | 0.0287 (16) | 0.0323 (17) | 0.0225 (15) | 0.0135 (13) | −0.0029 (13) | −0.0060 (13) |
C15 | 0.0200 (14) | 0.0341 (17) | 0.0224 (15) | 0.0122 (12) | 0.0022 (11) | 0.0025 (12) |
C16 | 0.0241 (15) | 0.0467 (19) | 0.0188 (15) | 0.0150 (14) | 0.0030 (12) | 0.0035 (13) |
C21 | 0.0147 (13) | 0.0277 (15) | 0.0225 (14) | 0.0077 (11) | 0.0030 (11) | 0.0062 (12) |
C22 | 0.0184 (14) | 0.0277 (16) | 0.0289 (16) | −0.0002 (12) | 0.0008 (12) | 0.0008 (13) |
C23 | 0.0210 (15) | 0.0354 (18) | 0.0356 (18) | −0.0041 (13) | 0.0035 (13) | 0.0070 (14) |
C24 | 0.0181 (15) | 0.0411 (19) | 0.0359 (18) | 0.0004 (13) | 0.0063 (13) | 0.0155 (15) |
C25 | 0.0157 (14) | 0.0380 (17) | 0.0266 (16) | 0.0085 (12) | 0.0044 (12) | 0.0119 (13) |
C26 | 0.0217 (15) | 0.050 (2) | 0.0242 (16) | 0.0124 (14) | 0.0087 (12) | 0.0119 (14) |
C31 | 0.0112 (12) | 0.0213 (14) | 0.0190 (14) | −0.0024 (10) | 0.0048 (10) | 0.0003 (11) |
C32 | 0.0155 (13) | 0.0233 (14) | 0.0269 (15) | 0.0010 (11) | 0.0046 (11) | 0.0033 (12) |
C33 | 0.0179 (14) | 0.0200 (14) | 0.0299 (16) | 0.0013 (11) | 0.0070 (12) | −0.0029 (12) |
C34 | 0.0150 (13) | 0.0261 (15) | 0.0242 (15) | −0.0018 (12) | 0.0063 (11) | −0.0029 (12) |
C35 | 0.0128 (13) | 0.0243 (14) | 0.0220 (14) | −0.0023 (11) | 0.0057 (11) | 0.0023 (11) |
C36 | 0.0136 (13) | 0.0342 (16) | 0.0202 (14) | −0.0010 (12) | 0.0026 (11) | 0.0048 (12) |
C41 | 0.0093 (12) | 0.0196 (14) | 0.0253 (15) | −0.0007 (10) | 0.0054 (11) | 0.0033 (11) |
C42 | 0.0218 (15) | 0.0239 (15) | 0.0295 (16) | 0.0022 (12) | 0.0102 (12) | 0.0016 (12) |
C43 | 0.0239 (15) | 0.0226 (15) | 0.0429 (19) | 0.0070 (12) | 0.0095 (13) | 0.0030 (13) |
C44 | 0.0182 (14) | 0.0258 (16) | 0.0417 (19) | 0.0045 (12) | 0.0061 (13) | 0.0128 (14) |
C45 | 0.0109 (13) | 0.0235 (15) | 0.0296 (16) | −0.0003 (11) | 0.0050 (11) | 0.0088 (12) |
C46 | 0.0131 (14) | 0.0341 (17) | 0.0273 (16) | 0.0008 (12) | 0.0021 (11) | 0.0099 (13) |
B1 | 0.0267 (17) | 0.0255 (17) | 0.0277 (18) | 0.0059 (14) | 0.0025 (14) | −0.0003 (14) |
F1 | 0.0482 (11) | 0.0292 (10) | 0.0315 (10) | 0.0103 (8) | 0.0090 (8) | 0.0089 (8) |
F2 | 0.0430 (11) | 0.0462 (12) | 0.0393 (11) | 0.0186 (9) | 0.0030 (9) | −0.0107 (9) |
F3 | 0.0244 (9) | 0.0370 (10) | 0.0512 (12) | 0.0028 (8) | 0.0024 (8) | 0.0130 (9) |
F4 | 0.0317 (10) | 0.0371 (10) | 0.0320 (10) | 0.0081 (8) | −0.0045 (8) | 0.0002 (8) |
Cu1—N30 | 1.989 (2) | C23—C24 | 1.359 (5) |
Cu1—N10 | 1.998 (2) | C23—H23 | 0.9500 |
Cu1—N1 | 1.996 (2) | C24—C25 | 1.407 (4) |
Cu1—N40 | 2.053 (2) | C24—H24 | 0.9500 |
Cu1—N20 | 2.134 (2) | C25—C26 | 1.428 (4) |
C1—N1 | 1.150 (4) | C26—H26 | 0.9500 |
C1—N3 | 1.288 (4) | C31—C35 | 1.402 (4) |
C2—N2 | 1.155 (4) | C31—C41 | 1.431 (4) |
C2—N3 | 1.318 (4) | C32—C33 | 1.397 (4) |
N10—C12 | 1.341 (4) | C32—H32 | 0.9500 |
N10—C11 | 1.356 (4) | C33—C34 | 1.371 (4) |
N20—C22 | 1.332 (4) | C33—H33 | 0.9500 |
N20—C21 | 1.356 (4) | C34—C35 | 1.410 (4) |
N30—C32 | 1.329 (4) | C34—H34 | 0.9500 |
N30—C31 | 1.356 (3) | C35—C36 | 1.431 (4) |
N40—C42 | 1.323 (4) | C36—C46 | 1.359 (4) |
N40—C41 | 1.361 (4) | C36—H36 | 0.9500 |
C11—C15 | 1.398 (4) | C41—C45 | 1.398 (4) |
C11—C21 | 1.438 (4) | C42—C43 | 1.394 (4) |
C12—C13 | 1.388 (4) | C42—H42 | 0.9500 |
C12—H12 | 0.9500 | C43—C44 | 1.365 (4) |
C13—C14 | 1.374 (4) | C43—H43 | 0.9500 |
C13—H13 | 0.9500 | C44—C45 | 1.409 (4) |
C14—C15 | 1.406 (4) | C44—H44 | 0.9500 |
C14—H14 | 0.9500 | C45—C46 | 1.428 (4) |
C15—C16 | 1.437 (4) | C46—H46 | 0.9500 |
C16—C26 | 1.351 (5) | B1—F4 | 1.387 (4) |
C16—H16 | 0.9500 | B1—F1 | 1.395 (4) |
C21—C25 | 1.403 (4) | B1—F2 | 1.392 (4) |
C22—C23 | 1.396 (4) | B1—F3 | 1.399 (4) |
C22—H22 | 0.9500 | ||
N30—Cu1—N10 | 177.26 (9) | C22—C23—H23 | 120.2 |
N30—Cu1—N1 | 92.28 (9) | C23—C24—C25 | 119.6 (3) |
N10—Cu1—N1 | 89.94 (10) | C23—C24—H24 | 120.2 |
N30—Cu1—N40 | 81.96 (9) | C25—C24—H24 | 120.2 |
N10—Cu1—N40 | 97.52 (9) | C21—C25—C24 | 117.0 (3) |
N1—Cu1—N40 | 136.63 (10) | C21—C25—C26 | 119.1 (3) |
N30—Cu1—N20 | 97.32 (9) | C24—C25—C26 | 124.0 (3) |
N10—Cu1—N20 | 80.29 (9) | C16—C26—C25 | 121.4 (3) |
N1—Cu1—N20 | 113.96 (10) | C16—C26—H26 | 119.3 |
N40—Cu1—N20 | 109.41 (9) | C25—C26—H26 | 119.3 |
N1—C1—N3 | 173.5 (3) | N30—C31—C35 | 122.7 (2) |
N2—C2—N3 | 174.2 (3) | N30—C31—C41 | 116.9 (2) |
C1—N1—Cu1 | 144.2 (2) | C35—C31—C41 | 120.4 (2) |
C1—N3—C2 | 119.2 (3) | N30—C32—C33 | 122.1 (3) |
C12—N10—C11 | 118.3 (2) | N30—C32—H32 | 118.9 |
C12—N10—Cu1 | 126.4 (2) | C33—C32—H32 | 118.9 |
C11—N10—Cu1 | 115.12 (18) | C34—C33—C32 | 119.7 (3) |
C22—N20—C21 | 117.5 (2) | C34—C33—H33 | 120.1 |
C22—N20—Cu1 | 131.8 (2) | C32—C33—H33 | 120.1 |
C21—N20—Cu1 | 110.66 (18) | C33—C34—C35 | 119.3 (3) |
C32—N30—C31 | 118.8 (2) | C33—C34—H34 | 120.4 |
C32—N30—Cu1 | 127.82 (19) | C35—C34—H34 | 120.4 |
C31—N30—Cu1 | 113.37 (17) | C31—C35—C34 | 117.4 (3) |
C42—N40—C41 | 117.8 (2) | C31—C35—C36 | 118.4 (3) |
C42—N40—Cu1 | 130.9 (2) | C34—C35—C36 | 124.2 (3) |
C41—N40—Cu1 | 111.29 (17) | C46—C36—C35 | 121.1 (3) |
N10—C11—C15 | 122.9 (3) | C46—C36—H36 | 119.5 |
N10—C11—C21 | 116.9 (2) | C35—C36—H36 | 119.5 |
C15—C11—C21 | 120.1 (3) | N40—C41—C45 | 123.6 (2) |
N10—C12—C13 | 122.2 (3) | N40—C41—C31 | 116.5 (2) |
N10—C12—H12 | 118.9 | C45—C41—C31 | 119.9 (3) |
C13—C12—H12 | 118.9 | N40—C42—C43 | 122.8 (3) |
C14—C13—C12 | 119.8 (3) | N40—C42—H42 | 118.6 |
C14—C13—H13 | 120.1 | C43—C42—H42 | 118.6 |
C12—C13—H13 | 120.1 | C44—C43—C42 | 119.5 (3) |
C13—C14—C15 | 119.2 (3) | C44—C43—H43 | 120.3 |
C13—C14—H14 | 120.4 | C42—C43—H43 | 120.3 |
C15—C14—H14 | 120.4 | C43—C44—C45 | 119.8 (3) |
C11—C15—C14 | 117.5 (3) | C43—C44—H44 | 120.1 |
C11—C15—C16 | 118.9 (3) | C45—C44—H44 | 120.1 |
C14—C15—C16 | 123.6 (3) | C41—C45—C44 | 116.5 (3) |
C26—C16—C15 | 120.9 (3) | C41—C45—C46 | 118.9 (3) |
C26—C16—H16 | 119.6 | C44—C45—C46 | 124.6 (3) |
C15—C16—H16 | 119.6 | C36—C46—C45 | 121.2 (3) |
N20—C21—C25 | 123.4 (3) | C36—C46—H46 | 119.4 |
N20—C21—C11 | 117.0 (2) | C45—C46—H46 | 119.4 |
C25—C21—C11 | 119.6 (3) | F4—B1—F1 | 109.9 (3) |
N20—C22—C23 | 122.8 (3) | F4—B1—F2 | 109.7 (3) |
N20—C22—H22 | 118.6 | F1—B1—F2 | 109.1 (3) |
C23—C22—H22 | 118.6 | F4—B1—F3 | 109.4 (3) |
C24—C23—C22 | 119.7 (3) | F1—B1—F3 | 108.4 (3) |
C24—C23—H23 | 120.2 | F2—B1—F3 | 110.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C33—H33···F4 | 0.95 | 2.49 | 3.261 (3) | 138 |
C32—H32···F2 | 0.95 | 2.59 | 3.484 (3) | 158 |
C46—H46···F3i | 0.95 | 2.35 | 3.198 (3) | 148 |
C33—H33···F4ii | 0.95 | 2.53 | 3.173 (3) | 125 |
C34—H34···F1ii | 0.95 | 2.35 | 3.292 (3) | 171 |
C12—H12···F1iii | 0.95 | 2.28 | 3.154 (4) | 153 |
C22—H22···F3iv | 0.95 | 2.43 | 3.107 (3) | 128 |
C43—H43···F3v | 0.95 | 2.53 | 3.274 (3) | 135 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+2, −z+1; (iii) x, y−1, z; (iv) x+1, y, z; (v) x+1, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C2N3)(C12H8N2)2]BF4 |
Mr | 576.81 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 110 |
a, b, c (Å) | 8.0601 (8), 9.2246 (9), 16.4286 (15) |
α, β, γ (°) | 92.344 (7), 96.656 (8), 103.097 (8) |
V (Å3) | 1178.8 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.99 |
Crystal size (mm) | 0.40 × 0.35 × 0.30 |
Data collection | |
Diffractometer | Oxford Diffraction MODEL? CCD |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2007) |
Tmin, Tmax | 0.693, 0.755 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8578, 4116, 3555 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.119, 1.00 |
No. of reflections | 4116 |
No. of parameters | 352 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.98, −0.40 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2007), CrysAlis RED (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2001), PARST (Nardelli, 1983) and SHELXL97 (Sheldrick, 2008).
Cu1—N30 | 1.989 (2) | C1—N1 | 1.150 (4) |
Cu1—N10 | 1.998 (2) | C1—N3 | 1.288 (4) |
Cu1—N1 | 1.996 (2) | C2—N2 | 1.155 (4) |
Cu1—N40 | 2.053 (2) | C2—N3 | 1.318 (4) |
Cu1—N20 | 2.134 (2) | ||
N30—Cu1—N10 | 177.26 (9) | N10—Cu1—N20 | 80.29 (9) |
N30—Cu1—N1 | 92.28 (9) | N1—Cu1—N20 | 113.96 (10) |
N10—Cu1—N1 | 89.94 (10) | N40—Cu1—N20 | 109.41 (9) |
N30—Cu1—N40 | 81.96 (9) | N1—C1—N3 | 173.5 (3) |
N10—Cu1—N40 | 97.52 (9) | N2—C2—N3 | 174.2 (3) |
N1—Cu1—N40 | 136.63 (10) | C1—N1—Cu1 | 144.2 (2) |
N30—Cu1—N20 | 97.32 (9) |
D—H···A | D—H | H···A | D···A | D—H···A |
C33—H33···F4 | 0.95 | 2.49 | 3.261 (3) | 138 |
C32—H32···F2 | 0.95 | 2.59 | 3.484 (3) | 158 |
C46—H46···F3i | 0.95 | 2.35 | 3.198 (3) | 148 |
C33—H33···F4ii | 0.95 | 2.53 | 3.173 (3) | 125 |
C34—H34···F1ii | 0.95 | 2.35 | 3.292 (3) | 171 |
C12—H12···F1iii | 0.95 | 2.28 | 3.154 (4) | 153 |
C22—H22···F3iv | 0.95 | 2.43 | 3.107 (3) | 128 |
C43—H43···F3v | 0.95 | 2.53 | 3.274 (3) | 135 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+2, −z+1; (iii) x, y−1, z; (iv) x+1, y, z; (v) x+1, y−1, z. |
Understanding the shape of coordination polyhedra (SCP) in the case of five-coordination is one of the current problems in coordination chemistry (Murphy & Hathaway, 2003). The molecular structures of five-coordinated copper(II) complexes range from regular trigonal–bipyramidal to regular tetragonal–pyramidal, with most complexes falling between these two stereochemistries. In the majority of [CuX(L)2]Y complexes, where L are bidentate chelate bonded ligands and X and Y are anions of charge -1, the differences in stereochemistry may be associated with the differences in the ligands present (Youngme et al., 2007). A number of different structural approaches have been used in the past to describe the geometries of these compounds (Potočňák, Dunaj-Jurčo, Mikloš & Jäger, 2001, and references therein). In our search for possible reasons for different SCP in related compounds, we have previously studied the structures of five-coordinated copper(II) coordination compounds of the general formula [Cu(dca)(L)2]Y, where L is a bidentate chelate ligand 1,10-phenanthroline (phen) or 2,2'-bipyridine (bpy), dca is the dicyanamide anion, N(CN)2-, and Y is an anion of charge -1 (Potočňák et al., 2005). The SCP in these compounds is more or less distorted trigonal bipyramidal. However, we have found that the SCP is more distorted in compounds with bpy molecules than in those involving phen molecules. We suppose that the reason could be the different rigidity between highly rigid phen and less rigid bpy ligands. The title compound, [Cu(dca)(phen)2]BF4, (I), has been prepared as the next example within the framework of our ongoing studies. We present here the structure of (I) and compare it with the previously reported compound [Cu(dca)(bpy)2]BF4, (II) (Potočňák, Dunaj-Jurčo, Mikloš, Massa & Jäger, 2001).
Fig. 1 shows the structure and labelling scheme of one formula unit of (I). The Cu atom is coordinated by two chelate-like bound phen molecules in two axial [average Cu—N = 1.998 (3) Å] and two equatorial positions [average Cu—N = 2.09 (6) Å], whereas one terminal N atom of the dca ligand occupies the third equatorial position of a deformed trigonal bipyramid [Cu—N1 = 1.996 (2) Å]. The BF4- anion does not enter the inner coordination sphere. The same coordination of bpy and dca ligands and similar corresponding bond distances were also observed in (II).
Although the SCP around the Cu atoms in (I) and (II) are quite similar, they still differ in some details. The out-of-plane angles in (I) lie within the range 80.29 (9)–97.52 (9)°, similar to those observed in (II). The bond angles in the equatorial planes of (I) and (II) differ considerably from the ideal trigonal angle of 120°. If, according to the criteria of Harrison & Hathaway (1980), the angles N1—Cu—N20, N1—Cu—N40 and N20—Cu—N40 are labelled α1, α2 and α3, respectively, then the small angle α3 [109.41 (9)°], which is opposite to the Cu—N1 bond (N1 from the dca), and the rather large difference of 22.67° between α1 and α2, classify the coordination polyhedron around the Cu atom in (I) as trigonal bipyramidal, with a distortion towards square pyramidal. Atoms N10, N30 and N40 of the phen ligands and atom N1 of the dca represent the base of the distorted square pyramid thus formed [average Cu—N = 2.01 (3) Å], whereas atom N20, owing to the Jahn–Teller effect, occupies the axial position at a longer distance [2.134 (2) Å]. The same result can be obtained, of course, when using the τ parameter of Addison et al. (1984) as the criterion, which is 67.7 here (the τ parameter is 100 for an ideal trigonal bipyramid and 0 for an ideal square pyramid). For (II), the smaller value of the α3 angle [106.44 (11)°], and the larger difference of 36.45° between α1 and α2, indicate a greater distortion of the trigonal bipyramid towards a squre pyramid compared with (I). The smaller value of the τ parameter (54.2) confirms this increasing distortion. This may be seen as a confirmation of our hypothesis on the dependence of the SCP on the different rigidity of the chelate L ligands employed.
There are three canonical formulae describing the bonding mode in a dicyanamide ligand (Golub et al., 1986). Inspection of the bond lengths (Table 1) shows that the bonds associated with atom C1 are a little shorter than the bonds around atom C2. Nevertheless, both Ncyano≡C (C1≡ N1 and C2≡ N2) bond lengths in (I) are normal for an N≡C triple bond. On the other hand, the C2—N3 bond length is only slightly shorter than a single bond between an N atom and an sp-hybridized C atom [Standard value and reference?], whereas the C1—N3 bond length is only slightly longer than a double bond between an N atom and an sp-hybridized C atom [Standard value and reference?]. Therefore, no canonical formula correctly describes the bonding mode in the dicyanamide ligand in (I). In accordance with Golub et al. (1986), the bonding mode of the dicyanamide to the Cu atom can be considered as angular [C1—N1—Cu = 144.2 (2)°].
The BF4- anion remains uncoordinated, with B—F bond lengths and F—B—F angles typical for tetrafluoroborates (Cambridge Structural Database, Version? How many hits?; Allen, 2002). The anion is involved in numerous weak C—H···F hydrogen bonds which contribute to the stabilization of the crystal structure of (I). Those with a C—H···F angle greater than 120° and an H···F distance less than 2.6 Å are given in Table 2. Through these hydrogen bonds, cations and anions are interconnected to form layers along the (001) plane, as shown in Fig. 2.
Further stabilization of the structure may come from possible face-to-face π–π interactions between stacked phen molecules. There is a stacking interaction involving one phenyl and one pyridine ring of the phen ligands from neighbouring layers [that containing atoms N30 and N40 and its symmetry related layer at (1 - x, 1 - y, 1 - z)], with a centroid-to-centroid distance of 3.609 (4) Å. Another stacking interaction involves only the phenyl rings of the phen ligands from the same layer containing atoms N10 and N20 and its symmetry related layer at (1 - x, 1 - y, -z), with a centroid-to-centroid distance of 3.498 (4) Å.