A dynamic disorder-linked reversible phase transition in a new chloro­form solvate of cis-dichloridobis(triethyl­phosphane)platinum(II)

The title compound, cis-dichloridobis(triethyl­phosphane)platinum(II) chloro­form monosolvate, [PtCl₂(C₆H₁₅P)₂]·CHCl₃, has been obtained from ligand scrambling in the cis-[PtCl₂(Cyp₂PCl)(PEt₃)] (Cyp = cyclo­pent­yl) system in CHCl₃ solvent. Unlike the two previously reported unsolvated polymorphs, which are both monoclinic, the compound crystallizes in an ortho­rhom­bic setting. Furthermore, the system exhibits a reversible tem­perature-dependent structural phase transition, coupling a reduction in anisotropic displacement parameters and a reduction in crystallographic symmetry on cooling. The high-temperature phase adopts space group Pnma with the complex and solvent mol­ecules sitting across a crystallographic mirror plane (Z' = 0.5). The low-temperature phase adopts the space group P2₁2₁2₁ with Z' = 1.

S1. Comment

As part of our studies on hydrolysis/hydroxylation of chlorophosphane ligands in situ on platinum(II) centres (Cornet et al., 2011), we have prepared in solution the complex cis-[PtCl₂(Cyp₂PCl)(PEt₃)] (Cyp is cyclopentyl) and allowed it to hydrolyse slowly by exposure to air. During the hydrolysis process, however, the ³¹P NMR solution-state spectra of the reaction mixture demonstrated that ligand scrambling was occurring. Crystals suitable for single-crystal X-ray diffraction were isolated from the reaction mixture which proved to be a new 1:1 solvate of cis-[PtCl₂(PEt₃)₂] with CHCl₃, (1).

Analysis of the evolution of the length of the crystallographic c axis of (1) with temperature (Fig. 1) clearly demonstrates the onset of a phase transition at ~149 K. Data for the calculation of these unit-cell parameters were collected during continuous, very slow cooling (2 K h^-1); the data collections were such that equal amounts of reciprocal space were sampled for each data point, with the temperature of the data point being assigned to that at the mid-point of the scan. Each point on the graph therefore represents data recorded over ~1 K. Full data collections and structural determinations were then carried out above and below the phase-transition temperature at 220 K, (1a), and 120 K, (1b), respectively.

At 220 K, the space group of this solvated complex (1a) is Pnma, with a mirror plane bisecting both the Pt complex and the solvent molecule, resulting in a structure with Z' = 0.5. The CHCl₃ molecule shows dynamic disorder, rotating about the C—H bond axis in a symmetrical fashion with respect to the mirror plane.

Upon cooling below the phase transition the rotation of the solvent molecule ceases, with respect to the time scale of the diffraction experiment, and appears to `lock' into place. The CHCl<sub>3</sub> molecule is subsequently no longer symmetrical about a mirror plane, causing a reduction in the symmetry of the system. The structure of (1b) thus adopts the space group P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub> with Z' = 1 at 120 K. This transition is illustrated in Figs. 2 and 3. A whole-molecule twist, of both the complex and solvent molecules, with respect to the unit cell appears to be driven by a decrease in intermolecular distances, causing stronger Cl···H interactions. This results in movements of the ethyl `arms', further breaking the higher-temperature symmetry, as seen from the positions of atoms C32A/B in Fig. 2. The system reverts to the Pnma setting on returning to higher temperatures, demonstrating that the transition is fully reversible within the constraint that the temperature ramping rates are ≤ 120 K h^-1.

Electron-density maps (F_obs) through the mean plane defined by the Cl atoms of the chloroform molecule at the two temperatures are shown in Fig. 4, highlighting the decrease in dynamic disorder across the phase transition.

Selected bond distances and angles for (1a) and (1b) are listed in Table 1, together with data for one of the previously identified unsolvated monoclinic polymorphs, (2) (space group Cc), at 293 K (Otto & Muller, 2001) for which atomic coordinates are available. The second reported unsolvated polymorph (Caldwell et al., 1977) is not included in Table 1 as no three-dimensional coordinates are available, although Otto & Muller describe it as being isostructural with their cis-[PtCl₂(AsEt₃)₂] complex. These unsolvated polymorphs differ in the alignment of the PEt₃ groups to that found in both solvated polymorphs of (1).

The difference in orientation of the PEt₃ ligands around the Pt—P bonds may be better understood by considering the ethyl moiety that lies close to the coordination plane of the platinum atom. As in the case of the previously reported structures, there is one substituent on each phosphorus atom in (1) that lies very near this plane. However, unlike in the previously reported structures, these in-plane substituents point towards one another, as shown in the scheme. It may be expected that this arrangement of the ethyl groups will be somewhat sterically unfavourable, although it does give rise to an increased number of C—H···Cl interactions, mediated by the presence of the CHCl₃ solvent.

The packing motifs of the solvated and unsolvated structures are dominated by C—H···Cl interactions. In the case of (2) the only short intermolecular interaction is between C121—H12B···Cl1ⁱ [H···Cl = 2.905 Å; symmetry code: (i) x + 1/2, -y + 1/2, z + 1/2], which form one-dimensional chains along the [101] direction. In contrast, (1a) and (1b) form extended hydrogen-bonding networks (Tables 2 and 3); (1a) forms two-dimensional sheets which, upon cooling, interlink to give rise to the three-dimensional hydrogen-bonding network found in (1b), shown in Fig. 5.

The Pt—Cl distances (Table 1) are almost identical in all forms of the structure (1a), (1b) and (2), although the Pt—P bond lengths show some variation and are shorter in both forms of (1). The most instructive differences between (1) and (2) lie in the bond angles in the approximately squareplanar coordination geometry. While the Cl—Pt—Cl angles are very similar, the P—Pt—P angle is over 5° larger in the new polymorphs, reflecting the increased steric repulsion between the PEt₃ groups. There is far less variance in the Cl—Pt—P angles found in the polymorphs of (1) (all within 1°) compared with the monoclinic form, where they differ by > 6°, a result explained by the differing steric demands on the positions of the two Cl atoms in these structures. These effects may arise from the difference in alignment of the ethyl substituents on the PEt₃ ligands, compared with that in (2) described by Otto & Muller (2001). The geometrical parameters for (1a) and (1b) are similar to the literature data for other cis-[PtCl₂(PR₃)₂] complexes (Table 4).

Related literature

For related literature, see: Caldwell et al. (1977); Cosier & Glazer (1986); Dillon et al. (2010); Otto & Muller (2001).

S2. Experimental

During the synthesis of cis-[PtCl₂(PCyp₂Cl)(PEt₃)], all manipulations, including NMR sample preparation, were carried out either under an inert atmosphere of dry nitrogen or in vacuo, using standard Schlenk line or glove-box techniques. Chemicals of the best available commercial grade were used, in general without further purification. The ³¹P NMR spectra of all phosphorus-containing starting materials were recorded, to verify that no major impurities were present. The synthesis of trans-[PtCl(µ-Cl)(PEt₃)]₂ was carried out according to the literature procedure (Dillon et al., 2010). ³¹P NMR spectra were obtained on a Varian Mercury 400 Fourier-transform spectrometer at 161.91 MHz; chemical shifts are referenced to 85% H₃PO₄, with the high-frequency direction taken as positive.

Cyp₂PCl (0.042 ml, 0.22 mmol) was added via syringe to a solution of trans-[PtCl(µ-Cl)(PEt₃)]₂ (0.0840 g, 0.11 mmol) in CDCl₃ (1 ml). Formation of cis-[PtCl₂(P_BCyp₂Cl)(P_AEt₃)] was confirmed using ³¹P NMR spectroscopy: δP_A 13.6 p.p.m. (singlet + satellites, ¹J_Pt—P = 3506 Hz, ²J_P—P = 13 Hz), δP_B 113.0 p.p.m. (singlet + satellites, ¹J_Pt—P = 4024 Hz, ²J_P—P= 13 Hz). Attempted hydrolysis of this complex resulted in ligand scrambling to afford compound (1), cis-[PtCl₂(PEt₃)₂] (³¹P NMR: δ10.2 p.p.m. (singlet + satellites, ¹J_Pt—P = 3514 Hz)), and also cis-[PtCl₂(PCyp₂Cl)₂] (³¹P NMR: δ108.1ppm (singlet + satellites, ¹J_Pt—P = 4037 Hz)). Colourless crystals of (1) were obtained by slow evaporation of solvent from the reaction mixture. Crystals of (1) were also isolated from hydrolysis reactions of cis-[PtCl₂(PCy₂Cl)(PEt₃)] and cis-[PtCl₂(PCyCl₂)(PEt₃)] (Cy = cyclo-hexyl).

A crystal of (1) was mounted in inert oil and placed into the cold gas stream of a N₂ cryostream device (Cosier & Glazer, 1986) at 220 K. Data were collected at this temperature before ramping at a rate of 120 K h^-1 to 120 K, where the diffraction experiment was repeated. The temperature was again ramped at 120 K h^-1 to 220 K where a short data collection was performed to assess the reversibility of the transition.

S3. Refinement

H atoms were constrained to idealized geometries, riding on their associated C atoms, with fixed C—H distances (0.97–1.00 Å) and with U_iso(H) = 1.2U_eq(C) [or 1.5U_eq(C) for methyl H atoms]. On transforming to the low-temperature phase, the structure refinement indicated the presence of an inversion twin. The major twin fraction refined to 0.486 (5) and was subsequently fixed at 0.5. There are high values of the maximum and minimum residual electron density in (1a). These peaks (2.19 and -1.98 e A^-3, respectively) are located between the Cl atoms of the chloroform solvent molecule, and reflect the distribution of electron density shown in Fig. 4 (left), caused by the dynamic disorder of this fragment. These residual peaks serve to reinforce the conclusions drawn regarding the disorder and the phase transition.

Computing details

For both compounds, data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009). Software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009) for (1a); OLEX2 (Dolomanov et al. 2009) for (1b).

Figures

	Fig. 1. Graph showing evolution of the c-axis length of (1) with temperature.
	Fig. 2. The molecular structure of (1a) at 220 K (left, the mirror plane runs through atoms Pt1, Cl1S and C1S) and (1b) at 120 K (right). Atomic displacement parameters are shown at 50% probability in all crystallographic figures.
	Fig. 3. Projection of the crystal packing along the [100] direction of (1a) and (1b) (left and right, respectively), showing the shift in relative molecular orientations as well as the layered motif exhibited in both structures. H atoms have been omitted for clarity.
	Fig. 4. Electron-density maps (Fobs) through the mean plane defined by the Cl atoms of the chloroform solvent molecule in the structures at 220 K (left) and 120 K (right). Contour lines are displayed at 0.5 e Å^-3 intervals (higher contour levels have been omitted for clarity for the 120 K data).
	Fig. 5. Hydrogen-bonding networks of (1a) at 220 K (left) and (1b) at 120 K (right). The displayed intermolecular interactions were identified using the same threshold delta function in OLEX2 (Dolomanov et al., 2009) of 1.68 Å to highlight the difference between the structures either side of the phase transition. H atoms not involved in intermolecular contacts have been omitted for clarity.

(1a) cis-dichloridobis(triethylphosphine)platinum(II) chloroform monosolvate

Crystal data

[PtCl2(C6H15P)2]·CHCl3	Dx = 1.807 Mg m^−3
Mr = 621.66	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 5535 reflections
a = 19.0103 (9) Å	θ = 2.5–27.8°
b = 15.7378 (7) Å	µ = 6.86 mm^−1
c = 7.6394 (4) Å	T = 220 K
V = 2285.56 (19) Å^3	Block, colourless
Z = 4	0.21 × 0.20 × 0.18 mm
F(000) = 1208

Data collection

Bruker SMART CCD 1K area-detector diffractometer	2928 independent reflections
Radiation source: fine-focus sealed tube	2317 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.053
Detector resolution: 7.9 pixels mm^-1	θmax = 28.3°, θmin = 2.1°
ω scans	h = −25→24
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −20→19
Tmin = 0.759, Tmax = 1.0	l = −8→10
15061 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.105	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0491P)^2 + 14.4642P] where P = (Fo^2 + 2Fc^2)/3
2928 reflections	(Δ/σ)max = 0.001
103 parameters	Δρmax = 2.19 e Å^−3
0 restraints	Δρmin = −1.98 e Å^−3

Special details

Experimental. The data collection nominally covered a full sphere of reciprocal space by a combination of 4 sets of ω scans each set at different ϕ and/or 2θ angles and each scan (10.00 s exposure) covering -0.300\ degrees in ω. The crystal to detector distance was 4.424 cm.

R(int) was 0.0791 before and 0.0427 after absorption correction. The Ratio of minimum to maximum transmission is 0.759252. The λ/2 correction factor is 0.0000

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.

The large WGHT parameter and the low bond precision alerts are generated because the solvent molecule disorder was deliberately not refined as this study was designed to highlight the phase transition occurring.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Pt1	0.675107 (17)	0.2500	0.62106 (4)	0.02504 (11)
P1A	0.64589 (9)	0.13655 (10)	0.7858 (2)	0.0298 (3)
Cl1A	0.71140 (11)	0.14781 (12)	0.4133 (2)	0.0468 (4)
C21A	0.6063 (4)	0.1469 (4)	1.0030 (9)	0.0375 (15)
H21B	0.6379	0.1808	1.0765	0.045*
H21A	0.5621	0.1785	0.9915	0.045*
C31A	0.5837 (4)	0.0699 (4)	0.6672 (10)	0.0422 (17)
H31B	0.6059	0.0506	0.5584	0.051*
H31A	0.5735	0.0195	0.7380	0.051*
C22A	0.5909 (5)	0.0626 (5)	1.0976 (11)	0.060 (2)
H22B	0.5664	0.0741	1.2065	0.090*
H22C	0.6348	0.0336	1.1224	0.090*
H22A	0.5618	0.0270	1.0237	0.090*
C11A	0.7221 (4)	0.0685 (5)	0.8193 (11)	0.0476 (18)
H11A	0.7070	0.0165	0.8792	0.057*
H11B	0.7412	0.0522	0.7051	0.057*
C32A	0.5155 (5)	0.1136 (6)	0.6231 (13)	0.070 (3)
H32B	0.4930	0.1327	0.7300	0.105*
H32A	0.4847	0.0741	0.5628	0.105*
H32C	0.5248	0.1620	0.5481	0.105*
C12A	0.7799 (4)	0.1105 (6)	0.9261 (12)	0.059 (2)
H12A	0.7615	0.1268	1.0397	0.089*
H12B	0.7967	0.1606	0.8651	0.089*
H12C	0.8185	0.0709	0.9416	0.089*
C1S	0.3745 (6)	0.2500	1.1242 (16)	0.048 (3)
H1S	0.3231	0.2500	1.1451	0.058*
Cl1S	0.3914 (4)	0.2500	0.9134 (10)	0.341 (11)
Cl2S	0.4105 (3)	0.1635 (4)	1.2048 (14)	0.292 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pt1	0.02761 (18)	0.02415 (17)	0.02334 (17)	0.000	−0.00139 (13)	0.000
P1A	0.0343 (8)	0.0232 (7)	0.0320 (8)	−0.0015 (7)	−0.0013 (7)	0.0014 (6)
Cl1A	0.0544 (11)	0.0448 (10)	0.0411 (9)	−0.0038 (8)	0.0103 (8)	−0.0162 (8)
C21A	0.041 (4)	0.041 (4)	0.031 (3)	−0.005 (3)	0.003 (3)	0.005 (3)
C31A	0.049 (4)	0.034 (3)	0.045 (4)	−0.012 (3)	−0.003 (3)	−0.005 (3)
C22A	0.079 (6)	0.051 (5)	0.049 (5)	−0.020 (5)	−0.001 (4)	0.015 (4)
C11A	0.045 (4)	0.038 (4)	0.059 (5)	0.012 (3)	0.001 (4)	0.009 (4)
C32A	0.057 (5)	0.063 (6)	0.091 (7)	−0.003 (5)	−0.026 (5)	−0.018 (5)
C12A	0.045 (4)	0.074 (6)	0.060 (5)	0.014 (4)	−0.012 (4)	0.014 (5)
C1S	0.036 (5)	0.042 (6)	0.066 (7)	0.000	0.001 (5)	0.000
Cl1S	0.077 (4)	0.85 (3)	0.099 (5)	0.000	0.013 (4)	0.000
Cl2S	0.090 (3)	0.203 (6)	0.582 (15)	0.030 (3)	0.018 (6)	0.242 (8)

Geometric parameters (Å, º)

Pt1—P1A^i	2.2540 (16)	C31A—H31B	0.9800
Pt1—P1A	2.2540 (16)	C31A—H31A	0.9800
Pt1—Cl1A	2.3627 (17)	C22A—H22B	0.9700
Pt1—Cl1A^i	2.3627 (17)	C22A—H22C	0.9700
P1A—C21A	1.829 (7)	C22A—H22A	0.9700
P1A—C31A	1.821 (7)	C11A—H11A	0.9800
P1A—C11A	1.819 (7)	C11A—H11B	0.9800
C21A—C22A	1.538 (10)	C32A—H32B	0.9700
C31A—C32A	1.507 (12)	C32A—H32A	0.9700
C11A—C12A	1.520 (12)	C32A—H32C	0.9700
C1S—Cl1S	1.642 (14)	C12A—H12A	0.9700
C1S—Cl2S^i	1.643 (8)	C12A—H12B	0.9700
C1S—Cl2S	1.643 (8)	C12A—H12C	0.9700
C21A—H21B	0.9800	C1S—H1S	0.9900
C21A—H21A	0.9800
P1A—Pt1—P1A^i	104.77 (9)	H31B—C31A—H31A	107.6
P1A^i—Pt1—Cl1A	170.51 (7)	C21A—C22A—H22B	109.5
P1A—Pt1—Cl1A	84.71 (6)	C21A—C22A—H22C	109.5
P1A—Pt1—Cl1A^i	170.51 (7)	H22B—C22A—H22C	109.5
P1A^i—Pt1—Cl1A^i	84.72 (6)	C21A—C22A—H22A	109.5
Cl1A^i—Pt1—Cl1A	85.80 (10)	H22B—C22A—H22A	109.5
C21A—P1A—Pt1	122.5 (2)	H22C—C22A—H22A	109.5
C31A—P1A—Pt1	109.8 (3)	C12A—C11A—H11A	108.9
C31A—P1A—C21A	103.6 (3)	P1A—C11A—H11A	108.9
C22A—C21A—P1A	115.3 (5)	C12A—C11A—H11B	108.9
C11A—P1A—Pt1	110.4 (3)	P1A—C11A—H11B	108.9
C11A—P1A—C21A	104.6 (4)	H11A—C11A—H11B	107.7
C11A—P1A—C31A	104.3 (4)	C31A—C32A—H32B	109.5
C32A—C31A—P1A	114.0 (6)	C31A—C32A—H32A	109.5
C12A—C11A—P1A	113.3 (6)	H32B—C32A—H32A	109.5
Cl1S—C1S—Cl2S	106.6 (6)	C31A—C32A—H32C	109.5
Cl1S—C1S—Cl2S^i	106.6 (6)	H32B—C32A—H32C	109.5
Cl2S^i—C1S—Cl2S	111.9 (10)	H32A—C32A—H32C	109.5
C22A—C21A—H21B	108.4	C11A—C12A—H12A	109.5
P1A—C21A—H21B	108.4	C11A—C12A—H12B	109.5
C22A—C21A—H21A	108.4	H12A—C12A—H12B	109.5
P1A—C21A—H21A	108.4	C11A—C12A—H12C	109.5
H21B—C21A—H21A	107.5	H12A—C12A—H12C	109.5
C32A—C31A—H31B	108.7	H12B—C12A—H12C	109.5
P1A—C31A—H31B	108.7	Cl1S—C1S—H1S	110.5
C32A—C31A—H31A	108.7	Cl2S—C1S—H1S	110.5
P1A—C31A—H31A	108.7	Cl2S^i—C1S—H1S	110.5

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C21A—H21B···Cl1A^ii	0.98	2.97	3.717 (7)	134
C31A—H31A···Cl2S^iii	0.98	2.93	3.802 (9)	149
C1S—H1S···Cl1A^iv	0.99	2.70	3.505 (10)	139
C1S—H1S···Cl1A^v	0.99	2.70	3.505 (10)	138

Symmetry codes: (ii) x, y, z+1; (iii) −x+1, −y, −z+2; (iv) x−1/2, −y+1/2, −z+3/2; (v) x−1/2, y, −z+3/2.

(1b) cis-dichloridobis(triethylphosphine)platinum(II) chloroform monosolvate

Crystal data

[PtCl2(C6H15P)2]·CHCl3	Dx = 1.849 Mg m^−3
Mr = 621.66	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 6948 reflections
a = 18.9529 (9) Å	θ = 2.5–28.3°
b = 15.7268 (8) Å	µ = 7.02 mm^−1
c = 7.4934 (4) Å	T = 120 K
V = 2233.5 (2) Å^3	Block, colourless
Z = 4	0.21 × 0.20 × 0.18 mm
F(000) = 1208

Data collection

Bruker SMART CCD 1K area-detector diffractometer	5546 independent reflections
Radiation source: fine-focus sealed tube	5240 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
Detector resolution: 7.9 pixels mm^-1	θmax = 28.3°, θmin = 1.7°
ω scans	h = −25→23
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −20→20
Tmin = 0.757, Tmax = 1.000	l = −9→9
25676 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)] = 0.023	H-atom parameters constrained
wR(F^2) = 0.045	w = 1/[σ^2(Fo^2) + (0.0142P)^2 + 0.9726P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
5546 reflections	Δρmax = 0.91 e Å^−3
196 parameters	Δρmin = −1.02 e Å^−3
0 restraints	Absolute structure: fixed due to inversion twin
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.5

Special details

Experimental. The data collection nominally covered a full sphere of reciprocal space by a combination of 6 sets of ω scans each set at different ϕ and/or 2θ angles and each scan (10.00 s exposure) covering -0.300\ degrees in ω. The crystal to detector distance was 4.424 cm.

R(int) was 0.0786 before and 0.0443 after absorption correction. The Ratio of minimum to maximum transmission is 0.757430. The λ/2 correction factor is 0.0000

A non standard unit cell setting was used to maintain consistency with the higher temperature phase in space group Pnma.

The Pt1 – P1b inconsistency with the Hirshfeld test is believed to be due to Fourier termination errors.

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
Pt1	0.193474 (8)	0.243929 (8)	0.364760 (17)	0.01508 (4)
Cl1A	0.22137 (6)	0.33608 (6)	0.12473 (15)	0.0246 (2)
P1A	0.15305 (6)	0.36208 (6)	0.50042 (14)	0.0152 (2)
P1B	0.17255 (6)	0.13972 (6)	0.56457 (15)	0.0173 (2)
Cl1B	0.24816 (7)	0.13603 (7)	0.19350 (16)	0.0307 (3)
Cl2S	0.44128 (7)	0.16527 (8)	0.10031 (19)	0.0404 (3)
Cl3S	0.42004 (8)	0.32998 (9)	−0.06034 (18)	0.0450 (3)
Cl1S	0.41143 (8)	0.30983 (8)	0.32183 (17)	0.0419 (3)
C1S	0.3946 (2)	0.2625 (3)	0.1141 (6)	0.0256 (9)
H1S	0.3429	0.2507	0.1039	0.031*
C21A	0.1171 (2)	0.3608 (3)	0.7257 (6)	0.0209 (10)
H21A	0.0748	0.3238	0.7269	0.025*
H21B	0.1524	0.3351	0.8065	0.025*
C31A	0.0835 (2)	0.4122 (2)	0.3678 (6)	0.0221 (8)
H31B	0.0732	0.4692	0.4175	0.027*
H31A	0.1005	0.4199	0.2439	0.027*
C21B	0.1225 (2)	0.1563 (3)	0.7703 (6)	0.0202 (9)
H21D	0.1501	0.1940	0.8496	0.024*
H21C	0.0781	0.1861	0.7403	0.024*
C12A	0.2840 (2)	0.4104 (2)	0.6365 (7)	0.0232 (9)
H12A	0.3038	0.3569	0.5915	0.035*
H12B	0.2657	0.4016	0.7574	0.035*
H12C	0.3210	0.4540	0.6390	0.035*
C11A	0.2242 (2)	0.4394 (2)	0.5141 (6)	0.0211 (9)
H11A	0.2432	0.4495	0.3930	0.025*
H11B	0.2050	0.4939	0.5590	0.025*
C11B	0.2552 (2)	0.0947 (3)	0.6392 (8)	0.0299 (10)
H11D	0.2455	0.0523	0.7336	0.036*
H11C	0.2777	0.0645	0.5380	0.036*
C12B	0.3067 (3)	0.1606 (3)	0.7116 (6)	0.0322 (10)
H12D	0.3222	0.1978	0.6143	0.048*
H12F	0.3478	0.1316	0.7631	0.048*
H12E	0.2834	0.1946	0.8039	0.048*
C32A	0.0158 (2)	0.3599 (3)	0.3650 (8)	0.0415 (13)
H32B	−0.0194	0.3884	0.2901	0.062*
H32C	−0.0025	0.3544	0.4868	0.062*
H32A	0.0257	0.3033	0.3164	0.062*
C22B	0.1042 (3)	0.0748 (3)	0.8734 (7)	0.0352 (12)
H22A	0.0708	0.0407	0.8036	0.053*
H22C	0.0828	0.0899	0.9882	0.053*
H22B	0.1473	0.0418	0.8942	0.053*
C22A	0.0965 (3)	0.4476 (3)	0.7995 (6)	0.0290 (11)
H22D	0.0618	0.4742	0.7202	0.043*
H22F	0.1385	0.4838	0.8073	0.043*
H22E	0.0760	0.4407	0.9187	0.043*
C32B	0.0507 (3)	0.0763 (3)	0.4035 (7)	0.0346 (12)
H32E	0.0515	0.1259	0.3244	0.052*
H32F	0.0236	0.0898	0.5112	0.052*
H32D	0.0287	0.0283	0.3416	0.052*
C31B	0.1256 (3)	0.0530 (3)	0.4551 (6)	0.0271 (11)
H31C	0.1518	0.0361	0.3465	0.033*
H31D	0.1243	0.0033	0.5363	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pt1	0.01713 (7)	0.01275 (6)	0.01536 (6)	−0.00163 (6)	0.00011 (6)	−0.00073 (6)
Cl1A	0.0281 (5)	0.0272 (5)	0.0186 (5)	−0.0016 (4)	0.0021 (5)	0.0063 (5)
P1A	0.0174 (6)	0.0128 (5)	0.0155 (5)	−0.0002 (4)	−0.0032 (4)	0.0004 (4)
P1B	0.0157 (6)	0.0132 (5)	0.0231 (5)	−0.0003 (4)	0.0003 (4)	0.0007 (4)
Cl1B	0.0353 (7)	0.0209 (5)	0.0357 (6)	−0.0029 (5)	0.0147 (5)	−0.0077 (4)
Cl2S	0.0394 (7)	0.0317 (6)	0.0502 (8)	0.0083 (5)	−0.0126 (6)	−0.0068 (6)
Cl3S	0.0451 (8)	0.0457 (8)	0.0441 (7)	−0.0061 (6)	0.0030 (7)	0.0158 (6)
Cl1S	0.0454 (8)	0.0432 (7)	0.0371 (7)	−0.0049 (6)	−0.0011 (6)	−0.0123 (5)
C1S	0.022 (2)	0.023 (2)	0.032 (2)	−0.0020 (17)	−0.0046 (17)	0.000 (2)
C21A	0.022 (2)	0.018 (2)	0.023 (2)	0.0018 (18)	−0.0036 (19)	0.0009 (18)
C31A	0.023 (2)	0.0213 (18)	0.023 (2)	0.0025 (16)	0.000 (2)	0.001 (2)
C21B	0.024 (3)	0.017 (2)	0.020 (2)	−0.0038 (17)	−0.0003 (18)	0.0039 (17)
C12A	0.017 (2)	0.0242 (19)	0.028 (2)	−0.0037 (15)	−0.005 (2)	−0.005 (2)
C11A	0.025 (2)	0.015 (2)	0.023 (2)	−0.0027 (17)	−0.0041 (19)	0.0006 (16)
C11B	0.023 (2)	0.022 (2)	0.045 (3)	0.0055 (17)	−0.001 (3)	0.014 (2)
C12B	0.025 (2)	0.035 (2)	0.037 (2)	0.006 (2)	−0.005 (2)	0.009 (2)
C32A	0.028 (3)	0.042 (3)	0.054 (3)	−0.009 (2)	−0.022 (3)	0.014 (3)
C22B	0.042 (3)	0.035 (2)	0.028 (3)	−0.006 (2)	0.005 (3)	0.011 (2)
C22A	0.027 (3)	0.029 (2)	0.031 (3)	0.002 (2)	−0.001 (2)	−0.008 (2)
C32B	0.030 (3)	0.035 (3)	0.038 (3)	−0.011 (2)	0.003 (2)	−0.011 (2)
C31B	0.035 (3)	0.015 (2)	0.031 (3)	−0.0074 (19)	0.009 (2)	−0.0058 (18)

Geometric parameters (Å, º)

Pt1—Cl1A	2.3696 (10)	C21B—H21C	0.9900
Pt1—P1A	2.2524 (11)	C12A—H12A	0.9800
Pt1—P1B	2.2550 (11)	C12A—H12B	0.9800
Pt1—Cl1B	2.3665 (11)	C12A—H12C	0.9800
P1A—C21A	1.821 (5)	C11A—H11A	0.9900
P1A—C31A	1.830 (4)	C11A—H11B	0.9900
P1A—C11A	1.818 (4)	C11B—H11D	0.9900
P1B—C21B	1.828 (4)	C11B—H11C	0.9900
P1B—C11B	1.808 (4)	C12B—H12D	0.9800
P1B—C31B	1.824 (4)	C12B—H12F	0.9800
Cl2S—C1S	1.770 (4)	C12B—H12E	0.9800
Cl3S—C1S	1.752 (4)	C32A—H32B	0.9800
Cl1S—C1S	1.755 (4)	C32A—H32C	0.9800
C21A—C22A	1.524 (6)	C32A—H32A	0.9800
C31A—C32A	1.524 (6)	C22B—H22A	0.9800
C21B—C22B	1.536 (6)	C22B—H22C	0.9800
C12A—C11A	1.529 (6)	C22B—H22B	0.9800
C11B—C12B	1.523 (6)	C22A—H22D	0.9800
C32B—C31B	1.516 (6)	C22A—H22F	0.9800
C1S—H1S	1.0000	C22A—H22E	0.9800
C21A—H21A	0.9900	C32B—H32E	0.9800
C21A—H21B	0.9900	C32B—H32F	0.9800
C31A—H31B	0.9900	C32B—H32D	0.9800
C31A—H31A	0.9900	C31B—H31C	0.9900
C21B—H21D	0.9900	C31B—H31D	0.9900
P1A—Pt1—Cl1A	85.06 (4)	H12A—C12A—H12B	109.5
P1A—Pt1—P1B	103.89 (4)	C11A—C12A—H12C	109.5
P1A—Pt1—Cl1B	170.15 (4)	H12A—C12A—H12C	109.5
P1B—Pt1—Cl1A	171.01 (4)	H12B—C12A—H12C	109.5
P1B—Pt1—Cl1B	85.18 (4)	C12A—C11A—H11A	109.1
Cl1B—Pt1—Cl1A	85.94 (4)	P1A—C11A—H11A	109.1
Cl3S—C1S—Cl2S	110.0 (2)	C12A—C11A—H11B	109.1
Cl3S—C1S—Cl1S	110.8 (2)	P1A—C11A—H11B	109.1
Cl1S—C1S—Cl2S	109.1 (2)	H11A—C11A—H11B	107.8
C21A—P1A—Pt1	122.47 (14)	C12B—C11B—H11D	108.9
C21A—P1A—C31A	103.8 (2)	P1B—C11B—H11D	108.9
C31A—P1A—Pt1	110.81 (14)	C12B—C11B—H11C	108.9
C21B—P1B—Pt1	123.20 (14)	P1B—C11B—H11C	108.9
C12A—C11A—P1A	112.6 (3)	H11D—C11B—H11C	107.7
C11A—P1A—Pt1	108.96 (15)	C11B—C12B—H12D	109.5
C11A—P1A—C21A	103.5 (2)	C11B—C12B—H12F	109.5
C11A—P1A—C31A	106.10 (18)	H12D—C12B—H12F	109.5
C11B—P1B—Pt1	109.72 (16)	C11B—C12B—H12E	109.5
C11B—P1B—C21B	104.2 (2)	H12D—C12B—H12E	109.5
C11B—P1B—C31B	105.6 (2)	H12F—C12B—H12E	109.5
C12B—C11B—P1B	113.5 (3)	C31A—C32A—H32B	109.5
C32A—C31A—P1A	112.5 (3)	C31A—C32A—H32C	109.5
C22B—C21B—P1B	115.0 (3)	H32B—C32A—H32C	109.5
C22A—C21A—P1A	115.0 (3)	C31A—C32A—H32A	109.5
C32B—C31B—P1B	113.0 (3)	H32B—C32A—H32A	109.5
C31B—P1B—Pt1	109.33 (16)	H32C—C32A—H32A	109.5
C31B—P1B—C21B	103.4 (2)	C21B—C22B—H22A	109.5
Cl3S—C1S—H1S	109.0	C21B—C22B—H22C	109.5
Cl1S—C1S—H1S	109.0	H22A—C22B—H22C	109.5
Cl2S—C1S—H1S	109.0	C21B—C22B—H22B	109.5
C22A—C21A—H21A	108.5	H22A—C22B—H22B	109.5
P1A—C21A—H21A	108.5	H22C—C22B—H22B	109.5
C22A—C21A—H21B	108.5	C21A—C22A—H22D	109.5
P1A—C21A—H21B	108.5	C21A—C22A—H22F	109.5
H21A—C21A—H21B	107.5	H22D—C22A—H22F	109.5
C32A—C31A—P1A	112.5 (3)	C21A—C22A—H22E	109.5
C32A—C31A—H31B	109.1	H22D—C22A—H22E	109.5
P1A—C31A—H31B	109.1	H22F—C22A—H22E	109.5
C32A—C31A—H31A	109.1	C31B—C32B—H32E	109.5
P1A—C31A—H31A	109.1	C31B—C32B—H32F	109.5
H31B—C31A—H31A	107.8	H32E—C32B—H32F	109.5
C22B—C21B—P1B	115.0 (3)	C31B—C32B—H32D	109.5
C22B—C21B—H21D	108.5	H32E—C32B—H32D	109.5
P1B—C21B—H21D	108.5	H32F—C32B—H32D	109.5
C22B—C21B—H21C	108.5	C32B—C31B—H31C	109.0
P1B—C21B—H21C	108.5	P1B—C31B—H31C	109.0
H21D—C21B—H21C	107.5	C32B—C31B—H31D	109.0
C11A—C12A—H12A	109.5	P1B—C31B—H31D	109.0
C11A—C12A—H12B	109.5	H31C—C31B—H31D	107.8

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1S—H1S···Cl1A	1.00	2.67	3.482 (4)	138
C1S—H1S···Cl1B	1.00	2.63	3.466 (4)	141
C21A—H21B···Cl1A^i	0.99	2.72	3.606 (5)	149
C21A—H21A···Cl2S^ii	0.99	2.85	3.601 (5)	133
C12A—H12A···Cl1S	0.98	2.97	3.727 (5)	135
C32B—H32F···Cl1S^ii	0.98	2.93	3.797 (5)	148
C31B—H31D···Cl2S^iii	0.99	2.97	3.817 (4)	145

Symmetry codes: (i) x, y, z+1; (ii) x−1/2, −y+1/2, −z+1; (iii) −x+1/2, −y, z+1/2.