An enanti­omerically pure P-stereogenic bis­phosphine: (S,S)-ethyl­ene­bis[(2-methyl­phen­yl)phenyl­phosphine] (o-tolyl-DiPAMP)

In connection with a research program involving the synthesis, structure determination, reactivity and ability to coordinate to metal centres of chiral bis­phosphine ligands, we have synthesized and structurally characterized, by means of single-crystal X-ray diffraction analysis, the title compound {systematic name: (S,S)-(ethane-1,2-di­yl)bis­[(2-methyl­phen­yl)phenyl­phosphane], abbreviated as o-tolyl-DiPAMP}, C₂₈H₂₈P₂. So far, neither the free bisphosphine (DiPAMP) nor analogues that incorporate the ethyl­enebisphosphine frame have had their crystal structures reported. The investigated compound forms crystals which are isostructural with the bis­phosphine dioxide analogue [King et al. (2007). Acta Cryst. E63, o3278], despite the involvement of the dioxide in C—H...O(=P) hydrogen bonds and the lack of similar hydrogen bonds in the investigated crystal structure. In both mol­ecules, the P—C—C—P chain is in a trans conformation, extended further at both ends by one of the two P—C_ipso bonds. The planes of the phenyl and o-tolyl rings attached to the same P atom are nearly perpendicular to one another. Both crystal structures are mainly stabilized by dispersive inter­actions.

S1. Introduction

Optically active phosphines are known to play an important role in various metal-catalyzed asymmetric reactions (Etayo & Vidal-Ferran, 2013). Undoubtedly the most famous example of this class of chiral phosphine ligand is (R,R)-1,2-bis­[(o-meth­oxy­phenyl)­phenyl­phosphanyl]ethane (DiPAMP). The corresponding rhodium-based catalyst was the first asymmetric catalyst employed on an industrial scale for the production of the Parkinson's disease drug L-DOPA (Knowles et al., 1975). Despite this breakthrough discovery, relatively little attention has been paid to this class of molecules for many years (Carey, 2014). Following research work completed in AdvaChemLab, a series of P-chiral phosphine ligands were synthesized and investigated for their hydrogenation capability. To our surprise, neither the free bis­phosphine (DiPAMP) nor its analogues that maintain the ethyl­enebisphosphine frame have had their crystal structures reported. The presented structure of (S,S)-ethyl­enebis[(2-methyl­phenyl)­phenyl­phosphine], denoted o-tolyl-DiPAMP, is therefore believed to be the first example of a compound from this family in its enanti­omerically pure form.

S2. Experimental

S2.1. Synthesis and crystallization

o-Tolyl-DiPAMP was synthesized using a modified Appel reaction (Bergin et al., 2007). The corresponding racemic monophosphine was reacted under modified Appel conditions to give enanti­omerically pure monophosphine oxide. Subsequent reduction using tri­chloro­silane at an elevated temperature and in situ boronation furnished the monophosphine borane. Copper-mediated coupling gave the bis­phosphine borane, which was deprotected under standard conditions using di­ethyl­amine to give the target compound, o-tolyl-DiPAMP. More detailed information about the synthetic procedure is provided in supporting Information.

The oxygen sensitivity of bis­phosphines complicates the growing and handling a suitable crystal for X-ray analysis. It was found that slow evaporation of a solution of the title compound in tetra­hydro­furan under a gentle stream of nitro­gen gas gave suitable crystals after two weeks of growth.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. The positions of all H atoms were calculated geometrically and refined using a riding model, with C—H = 0.96 Å and U_iso(H) = 1.5U_eq(C) for methyl H atoms, and C—H = 0.93 (phenyl) or 0.97 Å (ethyl), and with U_iso(H) = 1.2U_eq(C) for all other H atoms. The absolute structure was determined on the basis of the Flack parameter [x = -0.007 (17); Flack, 1983].

S3. Results and discussion

Crystals of the title compound, o-tolyl-DiPAMP, are chiral on the P atoms and contain solely the S,S enanti­omer. In the Cambridge Structural Database (CSD; Version ???; Allen, 2002), we found only two crystal structures of an enanti­omerically pure, chiral on P, noncyclic bis­(di­aryl­phosphine), namely (S,S)-1,3-bis­[(2-amino­phenyl)­phenyl­phosphino]propane (CSD refcode CUTZUM; Ansell et al., 1985) and (R,R)-ethyl­enebis[(2-methyl­phenyl)­phenyl­phosphine dioxide] (denoted o-tolyl-DiPAMPO; CSD refcode SIHDET; King et al. (2007). The investigated o-tolyl-DiPAMP crystals, possessing the S,S configuration, are isostructural with the latter crystals. The S and R designations has been reversed (according to the Cahn–Ingold–Prelog naming system; Cahn et al., 1966) because in the dioxide the lone electron pair on the chiral phospho­rus centre is replaced by an P atom, making it the highest priority, instead of the lowest.

The isostructurality index I_d (Fábián & Kálmán, 1999), calculated with the SimMK program (Kowiel, 2011), has a value of 96.7 (2)%. The ability of a phosphine derivative to form solid solutions with its dioxide analogue has been noted previously by Mohamed et al. (2004).

Parameters describing the molecular geometry around the P atoms in o-tolyl-DiPAMP are compared with the analogous data for o-tolyl-DiPAMPO in Table 2. Although in both structures the values of the C—P—C angles are significantly less than the tetra­hedral value, they are consistently smaller in o-tolyl-DiPAMP than in o-tolyl-DiPAMPO. Combined with this is a significant lengthening of the P—C bond [average values = 1.844 (4) and 1.812 (4) Å in o-tolyl-DiPAMP and o-tolyl-DiPAMPO, respectively] and a more widely spread distribution of the values of the exocyclic C_ortho—C_ipso—P valence angles. The described geometrical differences between the two closely related molecules illustrate a space-demanding effect of a lone pair at the P atoms in o-tolyl-DiPAMP.

In both compounds, the P—C—C—P chain adopts an extended trans conformation. Of the two P—C_ipso bonds attached to the same P atom, one always forms an extension to the zigzag chain defined by the P—C—C—P atoms. Inter­estingly, at one end of the molecule this extension is accomplished by the phenyl substituent, while at the other end , it is accomplished by the o-tolyl P—C_ipso bond, thus reducing the molecular symmetry from C₂ to C₁. Moreover, while this o-tolyl ring is nearly parallel to the P—C—C—P plane, the inter­planar angle being only 5.4 (2)°; its counterpart at the other P atom (i.e. the phenyl ring) is twisted around this bond and forms an angle of 57.2 (1)° with this plane. The planes of the phenyl and o-tolyl rings attached to the same P atom are nearly perpendicular to one another. The relative orientation of the like-substituents can be described as G⁺ (phenyl rings), G^- (o-tolyl rings) and T (the lone pairs); when viewed along the P1···P2 direction. The investigated compound forms crystals that are isostructural with those of its dioxide, despite an involvement of the dioxide in C—H···O(═P) hydrogen bonds and the lack thereof in the investigated crystal structure, as illustrated in Fig. 2.

Slight differences between the two structures are noticeable on the powder diffraction diagrams shown in Fig. 3. The patterns were calculated using Mecury (Macrae et al., 2006) from the known crystal structures and were stacked with identical scales on the abscissa using the KDif program (Knížek, 2005). Using a Hirshfeld surface analysis (McKinnon et al., 2004) implemented in CrystalExplorer (Wolff et al., 2007), we were able to qu­antify the amount of molecular surface involved in various inter­action types. It appeared that the H···H dispersion inter­actions involve 68% of the molecular surface area, while in the dioxide analogue this percentage is lower (61%) in favour of C—H···O(═P) hydrogen bonds, which involve almost 9% of the molecular surface area. Second in rank are weak C—H···π inter­actions nearly equally distributed in both compounds, engaging 29 and 30% of the surface area of the o-tolyl-DiPAMP and o-tolyl-DiPAMPO molecules, respectively. The arrangement of the molecules in both types of crystals is compared in Fig. 2. It can be seen that the resulting structure of o-tolyl-DiPAMP is consistent with directionality of C—H(ethyl­ene)···O(═P) hydrogen bonds observed in the crystals of o-tolyl-DiPAMPO, indicating that in the former crystals, the immediate acceptor of a hydrogen bond from the ethyl­ene H atoms there is some negative charge accumulated in a lone-pair region. However, the molecular surface area engaged in these H···P inter­actions is very small and amounts to only 2.4%. We are currently investigating the asymmetric catalytic potential of Rh, Ru and Ir complexes of o-tolyl-DiPAMP and o-tolyl-DiPAMPO.

Related literature

For related literature, see: Allen (2002); Ansell et al. (1985); Bergin et al. (2007); Cahn et al. (1966); Carey (2014); Etayo & Vidal-Ferran (2013); Fábián & Kálmán (1999); Flack (1983); King et al. (2007); Knížek (2005); Knowles et al. (1975); Kowiel (2011); Macrae et al. (2006); McKinnon et al. (2004); Mohamed et al. (2004); Wolff et al. (2007).

Computing details

Data collection: CrysAlis PRO (Agilent, 2013); cell refinement: CrysAlis PRO (Agilent, 2013); data reduction: CrysAlis PRO (Agilent, 2013); program(s) used to solve structure: SHELXS86 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006) and XP (Siemens, 1994); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Displacement ellipsoid representation (at the 40% probability level) of o-tolyl-DiPAMP in the crystal structure.
	Fig. 2. (a) Part of the crystal structure of o-tolyl-DIPAMP, showing the formation of a supramolecular motif analogous to (b) the C—H···O hydrogen-bonded dimers present in o-tolyl-DIPAMPO.
	Fig. 3. X-ray powder diffraction patterns calculated from the known crystal structures of o-tolyl-DiPAMP (blue) and o-tolyl-DiPAMPO (red). Both structures were determined at 100 K.

(S,S)-(Ethane-1,2-diyl)bis[(2-methylphenyl)phenylphosphane]

Crystal data

C28H28P2	F(000) = 904
Mr = 426.44	Dx = 1.216 Mg m^−3
Orthorhombic, P212121	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: P 2ac 2ab	Cell parameters from 9393 reflections
a = 5.9725 (1) Å	θ = 2.6–76.1°
b = 17.0935 (2) Å	µ = 1.77 mm^−1
c = 22.8179 (3) Å	T = 100 K
V = 2329.50 (6) Å^3	Needle, colourless
Z = 4	0.6 × 0.1 × 0.1 mm

Data collection

Agilent SuperNova Atlas diffractometer	4101 independent reflections
Radiation source: SuperNova (Cu) X-ray Source	4013 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.030
Detector resolution: 10.5357 pixels mm^-1	θmax = 66.6°, θmin = 4.7°
ω scans	h = −7→5
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2013)	k = −20→20
Tmin = 0.383, Tmax = 1.000	l = −25→27
10411 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.091	w = 1/[σ^2(Fo^2) + (0.0597P)^2 + 0.4488P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
4101 reflections	Δρmax = 0.37 e Å^−3
273 parameters	Δρmin = −0.30 e Å^−3
0 restraints	Absolute structure: Flack (1983), 1716 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.007 (17)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
P1	0.49729 (8)	0.94930 (3)	0.088442 (19)	0.02406 (13)
P2	0.87215 (8)	0.79349 (3)	0.21201 (2)	0.02412 (13)
C1	0.5845 (3)	0.89767 (10)	0.02119 (8)	0.0207 (4)
C2	0.7691 (3)	0.84772 (11)	0.01890 (8)	0.0230 (4)
H2	0.8648	0.8447	0.0510	0.028*
C3	0.8128 (3)	0.80221 (11)	−0.03043 (9)	0.0265 (4)
H3	0.9364	0.7691	−0.0312	0.032*
C4	0.6716 (3)	0.80655 (11)	−0.07822 (8)	0.0278 (4)
H4	0.6973	0.7752	−0.1108	0.033*
C5	0.4921 (3)	0.85751 (11)	−0.07762 (8)	0.0261 (4)
H5	0.4007	0.8612	−0.1105	0.031*
C6	0.4453 (3)	0.90355 (11)	−0.02853 (8)	0.0226 (4)
C7	0.2480 (3)	0.95806 (12)	−0.02966 (9)	0.0303 (4)
H7A	0.1614	0.9487	−0.0644	0.045*
H7B	0.3000	1.0112	−0.0296	0.045*
H7C	0.1567	0.9491	0.0043	0.045*
C8	0.5887 (3)	1.05044 (11)	0.07285 (8)	0.0231 (4)
C9	0.7971 (4)	1.06822 (12)	0.04972 (11)	0.0385 (5)
H9	0.8985	1.0282	0.0420	0.046*
C10	0.8558 (4)	1.14527 (13)	0.03804 (10)	0.0375 (5)
H10	0.9950	1.1565	0.0218	0.045*
C11	0.7083 (4)	1.20508 (12)	0.05037 (9)	0.0323 (5)
H11	0.7484	1.2568	0.0432	0.039*
C12	0.5015 (4)	1.18762 (12)	0.07343 (10)	0.0368 (5)
H12	0.4008	1.2277	0.0814	0.044*
C13	0.4420 (3)	1.11081 (12)	0.08479 (9)	0.0300 (4)
H13	0.3020	1.0998	0.1006	0.036*
C14	0.7097 (4)	0.91686 (11)	0.14227 (8)	0.0285 (4)
H14A	0.8569	0.9174	0.1243	0.034*
H14B	0.7115	0.9523	0.1754	0.034*
C15	0.6537 (4)	0.83361 (11)	0.16324 (8)	0.0278 (4)
H15A	0.6372	0.7997	0.1295	0.033*
H15B	0.5119	0.8344	0.1840	0.033*
C16	0.7597 (3)	0.69611 (11)	0.22942 (8)	0.0244 (4)
C17	0.5725 (4)	0.66581 (13)	0.20152 (10)	0.0338 (5)
H17	0.4914	0.6975	0.1761	0.041*
C18	0.5031 (4)	0.58908 (13)	0.21064 (11)	0.0420 (5)
H18	0.3767	0.5699	0.1916	0.050*
C19	0.6229 (5)	0.54176 (13)	0.24794 (11)	0.0438 (6)
H19	0.5788	0.4902	0.2540	0.053*
C20	0.8088 (5)	0.57098 (13)	0.27645 (10)	0.0431 (6)
H20	0.8876	0.5385	0.3019	0.052*
C23	0.8147 (3)	0.84800 (11)	0.27976 (8)	0.0237 (4)
C24	0.9765 (3)	0.90033 (11)	0.29878 (9)	0.0301 (4)
H24	1.1080	0.9061	0.2774	0.036*
C25	0.9451 (4)	0.94440 (13)	0.34947 (10)	0.0380 (5)
H25	1.0552	0.9792	0.3617	0.046*
C26	0.7509 (4)	0.93635 (12)	0.38142 (10)	0.0370 (5)
H26	0.7297	0.9654	0.4154	0.044*
C27	0.5871 (4)	0.88462 (13)	0.36261 (10)	0.0371 (5)
H27	0.4558	0.8791	0.3841	0.045*
C28	0.6174 (4)	0.84099 (13)	0.31198 (9)	0.0320 (4)
H28	0.5057	0.8070	0.2995	0.038*
C21	0.8820 (4)	0.64765 (12)	0.26830 (9)	0.0308 (4)
C22	1.0821 (5)	0.67819 (15)	0.30089 (11)	0.0474 (6)
H22A	1.0338	0.7140	0.3307	0.071*
H22B	1.1799	0.7048	0.2741	0.071*
H22C	1.1607	0.6353	0.3187	0.071*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.0317 (2)	0.0185 (2)	0.0220 (2)	0.0008 (2)	0.0060 (2)	−0.00025 (17)
P2	0.0289 (2)	0.0238 (2)	0.0197 (2)	−0.0048 (2)	0.00220 (19)	0.00001 (17)
C1	0.0270 (9)	0.0123 (8)	0.0226 (9)	−0.0016 (7)	0.0033 (7)	0.0000 (6)
C2	0.0258 (9)	0.0184 (9)	0.0248 (9)	−0.0013 (8)	−0.0003 (7)	0.0015 (7)
C3	0.0276 (9)	0.0207 (9)	0.0313 (10)	0.0020 (8)	0.0061 (8)	−0.0020 (7)
C4	0.0346 (10)	0.0243 (9)	0.0244 (10)	−0.0052 (8)	0.0075 (8)	−0.0053 (8)
C5	0.0297 (9)	0.0275 (10)	0.0211 (9)	−0.0066 (8)	0.0003 (8)	0.0008 (7)
C6	0.0243 (9)	0.0169 (9)	0.0266 (9)	−0.0030 (7)	0.0026 (7)	0.0021 (7)
C7	0.0273 (10)	0.0288 (11)	0.0347 (11)	0.0039 (9)	−0.0028 (8)	0.0030 (8)
C8	0.0323 (9)	0.0172 (9)	0.0197 (8)	−0.0004 (8)	0.0016 (7)	0.0013 (7)
C9	0.0401 (12)	0.0230 (11)	0.0525 (14)	0.0057 (9)	0.0163 (11)	0.0009 (9)
C10	0.0377 (12)	0.0265 (11)	0.0484 (13)	−0.0034 (9)	0.0103 (10)	0.0050 (9)
C11	0.0454 (12)	0.0186 (9)	0.0328 (10)	−0.0007 (9)	−0.0084 (9)	0.0038 (8)
C12	0.0427 (11)	0.0248 (10)	0.0430 (12)	0.0122 (10)	−0.0003 (11)	0.0004 (9)
C13	0.0317 (10)	0.0248 (10)	0.0336 (10)	0.0051 (8)	−0.0005 (8)	0.0026 (8)
C14	0.0420 (11)	0.0234 (10)	0.0202 (9)	−0.0029 (8)	0.0005 (8)	−0.0010 (7)
C15	0.0386 (11)	0.0246 (10)	0.0200 (9)	−0.0054 (9)	−0.0019 (8)	0.0026 (7)
C16	0.0314 (10)	0.0229 (9)	0.0189 (9)	−0.0008 (8)	0.0053 (8)	−0.0005 (7)
C17	0.0344 (10)	0.0317 (11)	0.0353 (11)	−0.0068 (9)	−0.0015 (9)	0.0005 (8)
C18	0.0415 (11)	0.0306 (11)	0.0540 (14)	−0.0115 (10)	0.0122 (12)	−0.0085 (10)
C19	0.0600 (15)	0.0188 (10)	0.0524 (14)	−0.0029 (11)	0.0294 (12)	−0.0028 (9)
C20	0.0682 (16)	0.0251 (11)	0.0361 (12)	0.0156 (11)	0.0124 (11)	0.0020 (9)
C23	0.0307 (9)	0.0186 (9)	0.0217 (9)	−0.0002 (7)	−0.0021 (7)	0.0013 (7)
C24	0.0299 (9)	0.0249 (10)	0.0354 (10)	−0.0023 (9)	−0.0002 (9)	−0.0028 (8)
C25	0.0437 (12)	0.0287 (11)	0.0415 (12)	−0.0006 (9)	−0.0107 (10)	−0.0116 (9)
C26	0.0561 (13)	0.0271 (11)	0.0278 (10)	0.0074 (10)	−0.0034 (10)	−0.0056 (8)
C27	0.0457 (12)	0.0364 (12)	0.0293 (11)	0.0009 (10)	0.0102 (9)	−0.0016 (9)
C28	0.0337 (10)	0.0329 (11)	0.0294 (10)	−0.0050 (9)	0.0028 (9)	−0.0022 (8)
C21	0.0416 (11)	0.0271 (10)	0.0237 (9)	0.0093 (9)	0.0038 (9)	−0.0045 (8)
C22	0.0580 (15)	0.0405 (13)	0.0438 (13)	0.0205 (12)	−0.0202 (12)	−0.0089 (10)

Geometric parameters (Å, º)

P1—C1	1.8454 (18)	C14—C15	1.538 (3)
P1—C8	1.8475 (19)	C14—H14A	0.9700
P1—C14	1.851 (2)	C14—H14B	0.9700
P2—C23	1.8374 (19)	C15—H15A	0.9700
P2—C16	1.8383 (19)	C15—H15B	0.9700
P2—C15	1.847 (2)	C16—C17	1.387 (3)
C1—C2	1.395 (3)	C16—C21	1.416 (3)
C1—C6	1.410 (3)	C17—C18	1.391 (3)
C2—C3	1.393 (3)	C17—H17	0.9300
C2—H2	0.9300	C18—C19	1.375 (4)
C3—C4	1.381 (3)	C18—H18	0.9300
C3—H3	0.9300	C19—C20	1.380 (4)
C4—C5	1.381 (3)	C19—H19	0.9300
C4—H4	0.9300	C20—C21	1.394 (3)
C5—C6	1.397 (3)	C20—H20	0.9300
C5—H5	0.9300	C23—C24	1.387 (3)
C6—C7	1.502 (3)	C23—C28	1.394 (3)
C7—H7A	0.9600	C24—C25	1.393 (3)
C7—H7B	0.9600	C24—H24	0.9300
C7—H7C	0.9600	C25—C26	1.377 (3)
C8—C13	1.381 (3)	C25—H25	0.9300
C8—C9	1.386 (3)	C26—C27	1.387 (3)
C9—C10	1.389 (3)	C26—H26	0.9300
C9—H9	0.9300	C27—C28	1.387 (3)
C10—C11	1.378 (3)	C27—H27	0.9300
C10—H10	0.9300	C28—H28	0.9300
C11—C12	1.375 (3)	C21—C22	1.502 (3)
C11—H11	0.9300	C22—H22A	0.9600
C12—C13	1.385 (3)	C22—H22B	0.9600
C12—H12	0.9300	C22—H22C	0.9600
C13—H13	0.9300
C1—P1—C8	101.77 (8)	C15—C14—H14B	109.8
C1—P1—C14	102.42 (9)	P1—C14—H14B	109.8
C8—P1—C14	101.87 (9)	H14A—C14—H14B	108.2
C23—P2—C16	102.08 (8)	C14—C15—P2	112.18 (14)
C23—P2—C15	100.76 (9)	C14—C15—H15A	109.2
C16—P2—C15	102.03 (9)	P2—C15—H15A	109.2
C2—C1—C6	118.65 (17)	C14—C15—H15B	109.2
C2—C1—P1	123.15 (14)	P2—C15—H15B	109.2
C6—C1—P1	117.93 (14)	H15A—C15—H15B	107.9
C3—C2—C1	121.34 (18)	C17—C16—C21	118.98 (19)
C3—C2—H2	119.3	C17—C16—P2	122.24 (15)
C1—C2—H2	119.3	C21—C16—P2	118.47 (15)
C4—C3—C2	119.58 (18)	C16—C17—C18	121.6 (2)
C4—C3—H3	120.2	C16—C17—H17	119.2
C2—C3—H3	120.2	C18—C17—H17	119.2
C3—C4—C5	120.01 (17)	C19—C18—C17	119.5 (2)
C3—C4—H4	120.0	C19—C18—H18	120.3
C5—C4—H4	120.0	C17—C18—H18	120.3
C4—C5—C6	121.22 (18)	C18—C19—C20	119.8 (2)
C4—C5—H5	119.4	C18—C19—H19	120.1
C6—C5—H5	119.4	C20—C19—H19	120.1
C5—C6—C1	119.13 (17)	C19—C20—C21	122.0 (2)
C5—C6—C7	119.50 (17)	C19—C20—H20	119.0
C1—C6—C7	121.37 (17)	C21—C20—H20	119.0
C6—C7—H7A	109.5	C24—C23—C28	118.67 (18)
C6—C7—H7B	109.5	C24—C23—P2	117.39 (15)
H7A—C7—H7B	109.5	C28—C23—P2	123.92 (15)
C6—C7—H7C	109.5	C23—C24—C25	121.0 (2)
H7A—C7—H7C	109.5	C23—C24—H24	119.5
H7B—C7—H7C	109.5	C25—C24—H24	119.5
C13—C8—C9	118.75 (18)	C26—C25—C24	119.9 (2)
C13—C8—P1	118.30 (14)	C26—C25—H25	120.0
C9—C8—P1	122.95 (15)	C24—C25—H25	120.0
C8—C9—C10	120.5 (2)	C25—C26—C27	119.6 (2)
C8—C9—H9	119.7	C25—C26—H26	120.2
C10—C9—H9	119.7	C27—C26—H26	120.2
C11—C10—C9	120.2 (2)	C26—C27—C28	120.6 (2)
C11—C10—H10	119.9	C26—C27—H27	119.7
C9—C10—H10	119.9	C28—C27—H27	119.7
C12—C11—C10	119.40 (19)	C27—C28—C23	120.2 (2)
C12—C11—H11	120.3	C27—C28—H28	119.9
C10—C11—H11	120.3	C23—C28—H28	119.9
C11—C12—C13	120.5 (2)	C20—C21—C16	118.2 (2)
C11—C12—H12	119.7	C20—C21—C22	120.7 (2)
C13—C12—H12	119.7	C16—C21—C22	121.1 (2)
C8—C13—C12	120.60 (19)	C21—C22—H22A	109.5
C8—C13—H13	119.7	C21—C22—H22B	109.5
C12—C13—H13	119.7	H22A—C22—H22B	109.5
C15—C14—P1	109.56 (14)	C21—C22—H22C	109.5
C15—C14—H14A	109.8	H22A—C22—H22C	109.5
P1—C14—H14A	109.8	H22B—C22—H22C	109.5
C8—P1—C1—C2	105.61 (16)	C23—P2—C15—C14	74.89 (15)
C14—P1—C1—C2	0.48 (17)	C16—P2—C15—C14	179.85 (14)
C8—P1—C1—C6	−80.48 (15)	C23—P2—C16—C17	112.25 (17)
C14—P1—C1—C6	174.39 (14)	C15—P2—C16—C17	8.32 (19)
C6—C1—C2—C3	−2.2 (3)	C23—P2—C16—C21	−74.22 (16)
P1—C1—C2—C3	171.71 (14)	C15—P2—C16—C21	−178.15 (15)
C1—C2—C3—C4	0.2 (3)	C21—C16—C17—C18	−0.3 (3)
C2—C3—C4—C5	1.9 (3)	P2—C16—C17—C18	173.18 (17)
C3—C4—C5—C6	−2.1 (3)	C16—C17—C18—C19	−0.3 (3)
C4—C5—C6—C1	0.0 (3)	C17—C18—C19—C20	0.7 (3)
C4—C5—C6—C7	−179.84 (17)	C18—C19—C20—C21	−0.6 (3)
C2—C1—C6—C5	2.0 (3)	C16—P2—C23—C24	141.02 (15)
P1—C1—C6—C5	−172.15 (13)	C15—P2—C23—C24	−114.05 (16)
C2—C1—C6—C7	−178.09 (17)	C16—P2—C23—C28	−40.48 (19)
P1—C1—C6—C7	7.7 (2)	C15—P2—C23—C28	64.45 (18)
C1—P1—C8—C13	134.48 (15)	C28—C23—C24—C25	0.9 (3)
C14—P1—C8—C13	−119.96 (16)	P2—C23—C24—C25	179.49 (17)
C1—P1—C8—C9	−45.44 (19)	C23—C24—C25—C26	−0.1 (3)
C14—P1—C8—C9	60.12 (19)	C24—C25—C26—C27	−0.4 (3)
C13—C8—C9—C10	−0.9 (3)	C25—C26—C27—C28	0.0 (3)
P1—C8—C9—C10	179.03 (19)	C26—C27—C28—C23	0.8 (3)
C8—C9—C10—C11	1.2 (4)	C24—C23—C28—C27	−1.3 (3)
C9—C10—C11—C12	−1.1 (3)	P2—C23—C28—C27	−179.74 (17)
C10—C11—C12—C13	0.7 (3)	C19—C20—C21—C16	0.0 (3)
C9—C8—C13—C12	0.5 (3)	C19—C20—C21—C22	178.8 (2)
P1—C8—C13—C12	−179.42 (17)	C17—C16—C21—C20	0.5 (3)
C11—C12—C13—C8	−0.4 (3)	P2—C16—C21—C20	−173.27 (15)
C1—P1—C14—C15	−77.81 (15)	C17—C16—C21—C22	−178.3 (2)
C8—P1—C14—C15	177.13 (13)	P2—C16—C21—C22	8.0 (3)
P1—C14—C15—P2	174.79 (10)