Racemic (RS_C,SR_S)-(2-{[1-allyl­oxy­carbonyl-3-(methyl­sulfanyl)prop­yl]iminometh­yl}phenyl-κ³S,N,C¹)chlorido­platinum(II)

The title compound, [Pt(C₁₅H₁₈NO₂S)Cl], was obtained by the cyclo­metallation reaction of cis-bis­(benzonitrile)dichlorido­platinum(II) with N-benzyl­idene-L-methio­nine allyl ester in refluxing toluene. The Pt^II atom has a square-planar geometry and is tetra-coordinated by the Cl atom and the C, N and S atoms from the benzyl­idene methio­nine ester ligand. In the crystal structure, the S atoms show opposite chiral configurations with respect to the α-carbon of the methio­nine, reducing steric repulsion between the methyl and allyl ester groups.

Key indicators

• Single-crystal X-ray study
• T = 180 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.020
• wR factor = 0.052
• Data-to-parameter ratio = 16.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.86
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C6     --  C13     ..       5.16 su
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         10
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         40

Alert level G
PLAT128_ALERT_4_G Non-standard setting of Space-group P21/c   ....      P21/n
PLAT793_ALERT_4_G The Model has Chirality at C28     (Verify) ....          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Research on cyclometallated complexes (Capapé et al., 2005; Riera et al., 2000) has been focused because of their fundamental applications as luminescent materials (Caubet et al., 2003) and catalysts for a range of cross-coupling reactions. Amino acids, possessing natural chiral backbone and strong coordinating groups, are one of the potent candidates for designing stable cyclometallated complexes with highly controlled stereo-structure (Severin et al., 1998). Here, we report the crystal structure of the platinum (II) complex (1), containing chiral methionine-derived C,N,S-terdentate ligand.

The crystal structure of title compound (1) is presented in Fig. 1. The Pt(II) atom is tetracoordinated in a square-planar environment by a Cl atom and C, N, S atoms from benzylidene methionine ester ligand. In the [Pt (C₁₅H₁₈NO₂S)Cl] (1), S atoms showed opposite chiral configurations to the α-carbon of methionine for reducing steric repulsion between methyl and allyl ester groups (Fig. 2).

Related literature

For cyclometallated benzylideneamine terdentate Pt^II complexes, see: Capapé et al. (2005); Caubet et al. (2003); Riera et al. (2000). For organometallic amino acid complexes, see: Severin et al. (1998).

S2. Experimental

The methionine-derived ligand was synthesized from three step reactions, esterification, deprotection, condensation using Fmoc-L-methionine as a starting material (Fig. 3). A suspension of cis-[PtCl₂(PhCN)₂] and methionine-derived ligand was refluxed under nitrogen atmosphere for 3 h. The crude mixture was purified by SiO₂ flash column chromatography. Single crystals for X-ray analyses were obtained from a CH₂Cl₂ solution.

S3. Refinement

H atoms were positioned geometrically and refined as riding atoms, with C_arene—H and C_allyl—H = 0.93 Å, C_methyl—H = 0.96 Å, C_alkyl—H = 0.97Å and C_α—H = 0.98 Å, and with U_iso(H) = 1.2U_eq(C_arene, C_alkyl) and U_iso(H) = 1.5U_eq(C_methyl). Electron density synthesis with coefficients F_o—Fc: Highest peak 1.36 at 0.0428, 0.4390, 0.1909 (0.86 Å from Pt1)

Computing details

Data collection: SMART (Bruker, 2003); 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: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. ORTEP drawing of (RC,SS)-1 with 50% probability displacement.
	Fig. 2. The packing structure of (1). Hydrogen atoms are omitted for clarity.
	Fig. 3. Synthetic scheme of the amino acid-derived ligand for 1.

(RS_C,SR_S)-(2-{[1-allyloxycarbonyl-3- (methylsulfanyl)propyl]iminomethyl}phenyl- κ³S,N,C¹)chloridoplatinum(II)

Crystal data

[Pt(C15H18NO2S)Cl]	F(000) = 968
Mr = 506.90	Dx = 2.098 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1024 reflections
a = 8.6000 (13) Å	θ = 2.8–26.0°
b = 9.5093 (14) Å	µ = 9.04 mm^−1
c = 19.679 (3) Å	T = 180 K
β = 94.398 (2)°	Prism, orange
V = 1604.6 (4) Å^3	0.50 × 0.10 × 0.10 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	3105 independent reflections
Radiation source: fine-focus sealed tube	2854 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
ω scans	θmax = 26.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −9→10
Tmin = 0.610, Tmax = 0.862	k = −11→11
12273 measured reflections	l = −24→24

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)] = 0.020	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.052	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.033P)^2 + 0.6405P] where P = (Fo^2 + 2Fc^2)/3
3105 reflections	(Δ/σ)max = 0.003
191 parameters	Δρmax = 1.36 e Å^−3
0 restraints	Δρmin = −0.48 e Å^−3

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
Pt1	0.456604 (14)	0.848674 (12)	0.309063 (6)	0.01942 (6)
S4	0.63428 (10)	0.87893 (9)	0.22448 (5)	0.02394 (18)
Cl1	0.60649 (11)	1.00955 (10)	0.37235 (5)	0.0338 (2)
C3	0.3033 (4)	0.8222 (3)	0.37990 (18)	0.0224 (7)
N4	0.3141 (3)	0.7078 (3)	0.26035 (14)	0.0222 (6)
C6	0.1849 (5)	0.9473 (5)	−0.0659 (2)	0.0518 (12)
H6A	0.1530	0.8793	−0.0980	0.062*
H6B	0.2203	1.0341	−0.0801	0.062*
O7	0.1383 (4)	0.8499 (3)	0.16257 (16)	0.0423 (7)
C9	0.2011 (4)	0.6636 (3)	0.29340 (19)	0.0258 (8)
H9	0.1318	0.5959	0.2752	0.031*
C11	0.1695 (5)	0.8600 (4)	0.4821 (2)	0.0331 (9)
H11	0.1639	0.9067	0.5234	0.040*
O12	0.2371 (3)	0.7266 (3)	0.07819 (13)	0.0377 (6)
C13	0.1798 (5)	0.9200 (5)	0.0011 (3)	0.0497 (11)
H13	0.2122	0.9893	0.0324	0.060*
C15	0.1855 (4)	0.7230 (3)	0.36017 (17)	0.0242 (7)
C16	0.5768 (4)	0.7677 (4)	0.15222 (17)	0.0277 (7)
H16A	0.5139	0.8229	0.1190	0.033*
H16B	0.6699	0.7388	0.1311	0.033*
C17	0.2223 (4)	0.7597 (4)	0.14303 (18)	0.0292 (8)
C18	0.0640 (4)	0.6922 (4)	0.40057 (19)	0.0322 (8)
H18	−0.0100	0.6246	0.3868	0.039*
C19	0.2922 (4)	0.8882 (4)	0.44249 (18)	0.0274 (7)
H19	0.3685	0.9524	0.4580	0.033*
C20	0.0548 (4)	0.7633 (4)	0.46131 (18)	0.0366 (9)
H20	−0.0277	0.7465	0.4881	0.044*
C21	0.1259 (5)	0.7871 (5)	0.0261 (2)	0.0469 (11)
H21A	0.1100	0.7217	−0.0116	0.056*
H21B	0.0264	0.8009	0.0453	0.056*
C27	0.8092 (4)	0.7906 (4)	0.2577 (2)	0.0355 (9)
H27A	0.7881	0.6922	0.2627	0.053*
H27B	0.8434	0.8298	0.3012	0.053*
H27C	0.8892	0.8029	0.2268	0.053*
C28	0.3198 (4)	0.6605 (3)	0.18980 (18)	0.0246 (8)
H28	0.2675	0.5689	0.1867	0.030*
C29	0.4852 (4)	0.6366 (3)	0.16894 (19)	0.0270 (8)
H29A	0.5436	0.5870	0.2056	0.032*
H29B	0.4793	0.5756	0.1293	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pt1	0.01859 (9)	0.02131 (9)	0.01877 (9)	−0.00125 (4)	0.00404 (6)	−0.00029 (4)
S4	0.0227 (4)	0.0254 (4)	0.0247 (5)	0.0004 (3)	0.0077 (3)	0.0000 (3)
Cl1	0.0320 (5)	0.0411 (5)	0.0291 (5)	−0.0148 (4)	0.0066 (4)	−0.0086 (4)
C3	0.0202 (18)	0.0253 (16)	0.0217 (18)	−0.0021 (13)	0.0012 (14)	0.0065 (13)
N4	0.0247 (15)	0.0216 (14)	0.0206 (14)	−0.0022 (11)	0.0042 (11)	−0.0008 (11)
C6	0.046 (3)	0.062 (3)	0.050 (3)	0.009 (2)	0.020 (2)	0.018 (2)
O7	0.0392 (17)	0.0494 (18)	0.0387 (17)	0.0171 (13)	0.0061 (14)	0.0016 (12)
C9	0.0243 (19)	0.0242 (18)	0.029 (2)	−0.0058 (13)	0.0012 (15)	−0.0004 (13)
C11	0.030 (2)	0.047 (2)	0.022 (2)	−0.0010 (16)	0.0050 (16)	−0.0026 (15)
O12	0.0289 (14)	0.0599 (18)	0.0244 (13)	0.0047 (13)	0.0030 (11)	0.0035 (12)
C13	0.036 (2)	0.052 (3)	0.062 (3)	0.007 (2)	0.005 (2)	0.001 (2)
C15	0.0224 (17)	0.0290 (18)	0.0211 (17)	−0.0015 (13)	0.0013 (13)	0.0021 (13)
C16	0.0244 (18)	0.036 (2)	0.0236 (17)	0.0017 (15)	0.0079 (14)	−0.0030 (15)
C17	0.0224 (18)	0.037 (2)	0.0287 (19)	−0.0002 (15)	0.0044 (14)	0.0039 (16)
C18	0.024 (2)	0.042 (2)	0.030 (2)	−0.0109 (16)	0.0030 (15)	0.0034 (17)
C19	0.0253 (19)	0.0330 (18)	0.0240 (18)	−0.0018 (15)	0.0021 (14)	−0.0021 (15)
C20	0.028 (2)	0.059 (3)	0.0234 (19)	−0.0062 (18)	0.0097 (15)	0.0058 (17)
C21	0.036 (2)	0.071 (3)	0.033 (2)	0.000 (2)	−0.0041 (18)	0.009 (2)
C27	0.0222 (19)	0.043 (2)	0.041 (2)	0.0063 (16)	0.0015 (16)	−0.0047 (18)
C28	0.029 (2)	0.0233 (18)	0.0219 (18)	−0.0019 (13)	0.0018 (15)	−0.0044 (12)
C29	0.027 (2)	0.0287 (18)	0.0255 (19)	0.0064 (14)	0.0037 (15)	−0.0075 (14)

Geometric parameters (Å, º)

Pt1—C3	2.006 (4)	C13—C21	1.446 (7)
Pt1—N4	2.009 (3)	C13—H13	0.9300
Pt1—Cl1	2.3037 (9)	C15—C18	1.392 (5)
Pt1—S4	2.3618 (9)	C16—C29	1.524 (5)
S4—C27	1.801 (4)	C16—H16A	0.9700
S4—C16	1.810 (3)	C16—H16B	0.9700
C3—C19	1.392 (5)	C17—C28	1.524 (5)
C3—C15	1.417 (5)	C18—C20	1.381 (5)
N4—C9	1.281 (4)	C18—H18	0.9300
N4—C28	1.464 (4)	C19—H19	0.9300
C6—C13	1.348 (6)	C20—H20	0.9300
C6—H6A	0.9300	C21—H21A	0.9700
C6—H6B	0.9300	C21—H21B	0.9700
O7—C17	1.204 (4)	C27—H27A	0.9600
C9—C15	1.446 (5)	C27—H27B	0.9600
C9—H9	0.9300	C27—H27C	0.9600
C11—C19	1.386 (5)	C28—C29	1.528 (5)
C11—C20	1.387 (5)	C28—H28	0.9800
C11—H11	0.9300	C29—H29A	0.9700
O12—C17	1.330 (4)	C29—H29B	0.9700
O12—C21	1.464 (5)
C3—Pt1—N4	80.72 (13)	O7—C17—O12	125.4 (3)
C3—Pt1—Cl1	94.46 (10)	O7—C17—C28	124.4 (3)
N4—Pt1—Cl1	175.18 (8)	O12—C17—C28	110.1 (3)
C3—Pt1—S4	179.20 (10)	C20—C18—C15	119.1 (3)
N4—Pt1—S4	98.56 (8)	C20—C18—H18	120.4
Cl1—Pt1—S4	86.26 (3)	C15—C18—H18	120.4
C27—S4—C16	100.53 (18)	C11—C19—C3	121.2 (3)
C27—S4—Pt1	104.77 (14)	C11—C19—H19	119.4
C16—S4—Pt1	109.27 (12)	C3—C19—H19	119.4
C19—C3—C15	116.5 (3)	C18—C20—C11	119.6 (3)
C19—C3—Pt1	130.7 (3)	C18—C20—H20	120.2
C15—C3—Pt1	112.8 (2)	C11—C20—H20	120.2
C9—N4—C28	117.6 (3)	C13—C21—O12	111.9 (4)
C9—N4—Pt1	115.8 (2)	C13—C21—H21A	109.2
C28—N4—Pt1	126.4 (2)	O12—C21—H21A	109.2
C13—C6—H6A	120.0	C13—C21—H21B	109.2
C13—C6—H6B	120.0	O12—C21—H21B	109.2
H6A—C6—H6B	120.0	H21A—C21—H21B	107.9
N4—C9—C15	117.4 (3)	S4—C27—H27A	109.5
N4—C9—H9	121.3	S4—C27—H27B	109.5
C15—C9—H9	121.3	H27A—C27—H27B	109.5
C19—C11—C20	121.1 (4)	S4—C27—H27C	109.5
C19—C11—H11	119.4	H27A—C27—H27C	109.5
C20—C11—H11	119.4	H27B—C27—H27C	109.5
C17—O12—C21	118.2 (3)	N4—C28—C17	109.0 (3)
C6—C13—C21	122.5 (5)	N4—C28—C29	113.6 (3)
C6—C13—H13	118.8	C17—C28—C29	114.2 (3)
C21—C13—H13	118.8	N4—C28—H28	106.5
C18—C15—C3	122.4 (3)	C17—C28—H28	106.5
C18—C15—C9	124.2 (3)	C29—C28—H28	106.5
C3—C15—C9	113.3 (3)	C16—C29—C28	116.4 (3)
C29—C16—S4	115.0 (2)	C16—C29—H29A	108.2
C29—C16—H16A	108.5	C28—C29—H29A	108.2
S4—C16—H16A	108.5	C16—C29—H29B	108.2
C29—C16—H16B	108.5	C28—C29—H29B	108.2
S4—C16—H16B	108.5	H29A—C29—H29B	107.4
H16A—C16—H16B	107.5
N4—Pt1—S4—C27	−107.41 (16)	C21—O12—C17—C28	165.9 (3)
Cl1—Pt1—S4—C27	72.70 (14)	C3—C15—C18—C20	1.8 (6)
Cl1—Pt1—S4—C16	179.70 (13)	C9—C15—C18—C20	−175.2 (3)
N4—Pt1—C3—C19	−176.3 (4)	C20—C11—C19—C3	1.1 (6)
Cl1—Pt1—C3—C19	3.6 (3)	C15—C3—C19—C11	−1.6 (5)
N4—Pt1—C3—C15	1.1 (2)	Pt1—C3—C19—C11	175.8 (3)
Cl1—Pt1—C3—C15	−179.0 (2)	C15—C18—C20—C11	−2.4 (6)
C3—Pt1—N4—C9	−1.8 (3)	C19—C11—C20—C18	1.0 (6)
S4—Pt1—N4—C9	178.5 (2)	C6—C13—C21—O12	128.9 (4)
C3—Pt1—N4—C28	172.9 (3)	C17—O12—C21—C13	90.1 (5)
S4—Pt1—N4—C28	−6.8 (3)	C9—N4—C28—C17	86.9 (4)
C28—N4—C9—C15	−173.0 (3)	Pt1—N4—C28—C17	−87.7 (3)
Pt1—N4—C9—C15	2.2 (4)	C9—N4—C28—C29	−144.4 (3)
C19—C3—C15—C18	0.1 (5)	Pt1—N4—C28—C29	40.9 (4)
Pt1—C3—C15—C18	−177.7 (3)	O7—C17—C28—N4	−9.1 (5)
C19—C3—C15—C9	177.5 (3)	O12—C17—C28—N4	174.3 (3)
Pt1—C3—C15—C9	−0.3 (4)	O7—C17—C28—C29	−137.4 (4)
N4—C9—C15—C18	176.1 (3)	O12—C17—C28—C29	46.0 (4)
N4—C9—C15—C3	−1.2 (4)	S4—C16—C29—C28	69.7 (4)
C27—S4—C16—C29	83.2 (3)	N4—C28—C29—C16	−78.1 (4)
Pt1—S4—C16—C29	−26.7 (3)	C17—C28—C29—C16	47.8 (4)
C21—O12—C17—O7	−10.6 (6)