trans-Bis[2-(amino­meth­yl)pyridine-κ2N,N′]platinum(II)] bis­(hexa­fluorido­phosphate)

Nishimura, H.; Matsushita, N.

doi:10.1107/S2414314618012361

metal-organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 9| September 2018| x181236

https://doi.org/10.1107/S2414314618012361

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trans-Bis[2-(aminomethyl)pyridine-κ²N,N′]platinum(II)] bis(hexafluoridophosphate)

Hajime Nishimura ^a and Nobuyuki Matsushita ^b ^*

^aDepartment of Chemistry, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan, and ^bDepartment of Chemistry & Research Center for Smart Molecules, Rikkyo University, Nishi-Ikebukuro 3-34-1, Toshima-ku, Tokyo, 171-8501, Japan
^*Correspondence e-mail: cnmatsu@rikkyo.ac.jp

Edited by O. Blacque, University of Zürich, Switzerland (Received 21 August 2018; accepted 31 August 2018; online 7 September 2018)

The title compound, [Pt(amp)₂](PF₆)₂ [amp = 2-(aminomethyl)pyridine, C₆H₈N₂], crystallizes in the space group P $[\overline{1}]$ with a half of one [Pt(amp)₂]²⁺ cation and one hexafluoridophosphate ion in the asymmetric unit. The Pt^II atom lies on an inversion centre and has a square-planar coordination sphere defined by two amino groups and two pyridine moieties of two 2-(aminomethyl)pyridine chelate ligands. The crystal structure of the title salt is composed of alternating rows of [Pt(amp)₂]²⁺ cations and PF₆⁻ anions. The crystal packing is stabilized by N—H⋯F hydrogen bonds between the amino groups and the hexafluoridophosphate anions. The PF₆ anion is disordered over two sets of sites with an occupancy ratio of 0.744 (6):0.256 (6).

Keywords: crystal structure; platinum(II) complex; 2-(aminomethyl)pyridine; hexafluoridophosphate; hydrogen bonding.

CCDC reference: 1864971

Structure description

trans-Bis[(2-(aminomethyl)pyridine-κ²N,N′)platinum(II)] bis(hexafluoridophosphate), [Pt(amp)₂](PF₆)₂ (amp = 2-(aminomethyl)pyridine), was prepared in order to elucidate the single-crystalline photochromism of [Pt(amp)₂] salts. One of them, [Pt(amp)₂]Cl₂·H₂O, has been reported as the first single-crystalline photochromic metal-complex salt (Nishimura & Matsushita, 2002 ). The title salt is the hexafluoridophosphate of trans-bis(2-(aminomethyl)pyridine-κ²N,N′)platinum(II) complex and does not display single-crystalline photochromic behavior under the same photo-irradiation conditions as [Pt(amp)₂]Cl₂·H₂O, i.e. under the visible light of a tungsten lamp.

The molecular components of the title salt are displayed in Fig. 1. The asymmetric unit comprises half of one [Pt(amp)₂]²⁺ cation and one hexafluoridophosphate anion. The Pt^II atom of [Pt(amp)₂]²⁺ cation lies on an inversion centre and is coordinated by four N atoms of two amino groups and two pyridine moieties of the two 2-(aminomethyl)pyridine chelate ligands in a trans configuration. The methylpyridine part of the 2-(aminomethyl)pyridine ligand forms a planar configuration with the r.m.s. deviation of the least-squares plane formed by atoms C1–C6 and N2 being 0.0066 Å. The dihedral angle between the methylpyridine plane and the [PtN₄] coordination plane is 10.4 (2)°. The [Pt(amp)₂]²⁺ cation does not adapt a co-planar configuration and is slightly distorted.

Figure 1
The structures of the molecular components of the title salt, showing the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level for non-H atoms. The green hollow F ellipsoids and the black hollow lines between P and F atoms represent the minor disorder component of the PF₆ anion [symmetry code: (i) −x, 1 − y, 1 − z].

The Pt—N_amine [2.044 (3) Å] and Pt—N_pyridine [2.013 (3) Å] bond lengths, and N—Pt—N [80.67 (12)°] bond angle in the chelate ring are consistent with those values reported for [Pt(amp)₂]Cl₂·H₂O [Pt—N_amine = 2.043 (5), 2.048 (4) Å, Pt—N_pyridine = 2.011 (4), 2.018 (4) Å, N—Pt—N = 81.06 (17), 81.33 (18)°; Nishimura & Matsushita, 2002].

The crystal structure of the title salt is composed of alternating rows of [Pt(amp)₂]²⁺ cations and PF₆⁻ anions (Fig. 2). The arrangement of the cations and anions in the crystal packing of the title salt is very similar to that of the chloride monohydrate, [Pt(amp)₂]Cl₂·H₂O (Nishimura & Matsushita, 2002). The N—H⋯F hydrogen bonds between the amino groups of [Pt(amp)₂]²⁺ cations and the fluorine atoms of the PF₆⁻ anions stabilize the crystal packing of the title salt (Fig. 3 and Table 1).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯F2ⁱ	0.89	2.40	3.080 (8)	133
N1—H1A⋯F4	0.89	2.24	2.971 (9)	139
N1—H1B⋯F6ⁱⁱ	0.89	2.46	3.233 (10)	146
N1—H1A⋯F2B	0.89	2.22	2.98 (2)	143
N1—H1B⋯F5Bⁱⁱ	0.89	2.05	2.84 (2)	148
Symmetry codes: (i) -x, -y+1, -z; (ii) x, y+1, z.

Figure 2
The crystal packing of the title salt, viewed along the b axis. Orange solid lines indicate the unit cell.

Figure 3
Hydrogen bonds between the amino groups of the 2-(aminomethyl)pyridine ligands of the platinum complex molecules and fluorine atoms of the hexafluoridophosphate anions, represented by light-blue dashed lines. Orange solid lines indicate the unit cell. The minor disordered parts of the PF₆ anions were omitted for clarify except for one site [symmetry codes: (ii) −x, 1 − y, −z; (iii) x, 1 + y, z; (iv) x, −1 + y, z].

Synthesis and crystallization

To a solution of [Pt(amp)₂]Cl₂·H₂O (216 mg) dissolved in water (60 ml) was slowly added a solution of NH₄PF₆ (150 mg) dissolved in water (40 ml). A short time later, slightly yellowish colourless needle-like crystals precipitated. The crystals were collected by filtration and air-dried. Yield: 158 mg (52%). Elemental analysis: found: C, 20.51; H, 2.28; N, 7.99%, calculated for C₁₂H₁₆F₁₂N₄P₂Pt: C, 20.55; H, 2.30; N, 7.99%. The elemental analysis was carried out by the Laboratory of Organic Elemental Analysis, Department of Chemistry, Graduate School of Science, The University of Tokyo. A single-crystal suitable for X-ray crystallography was chosen from the crystals collected.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The structure was refined as a two-component disordered structure of the PF₆ anion, the minor fluorine atoms of which were based on the positions of residual peaks. The occupancy ratio of 0.744 (6):0.256 (6) for the two orientations was obtained by refinement with a free variable. The maximum and minimum electron density peaks are located 0.76 and 0.68 Å, respectively, from the Pt atom.

Table 2
Experimental details

Crystal data
Chemical formula	[Pt(C₆H₈N₂)₂](PF₆)₂
M_r	701.32
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	296
a, b, c (Å)	7.3011 (3), 8.3055 (3), 9.2821 (3)
α, β, γ (°)	64.226 (4), 75.212 (5), 84.540 (6)
V (Å³)	489.99 (4)
Z	1
Radiation type	Mo Kα
μ (mm⁻¹)	7.44
Crystal size (mm)	0.41 × 0.29 × 0.12

Data collection
Diffractometer	Rigaku R-AXIS RAPID imaging-plate
Absorption correction	Integration (NUMABS; Rigaku, 1999 )
T_min, T_max	0.206, 0.508
No. of measured, independent and observed [I > 2σ(I)] reflections	12933, 3484, 3484
R_int	0.059
(sin θ/λ)_max (Å⁻¹)	0.757

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.028, 0.067, 1.05
No. of reflections	3484
No. of parameters	180
No. of restraints	48
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.92, −1.55
Computer programs: PROCESS-AUTO (Rigaku, 1998 ), RAPID-AUTO (Rigaku, 2015 ), SHELXT (Sheldrick, 2015a ), SHELXL2014 (Sheldrick, 2015b ), DIAMOND (Brandenburg, 2018 ) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1864971

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S2414314618012361/zq4030sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618012361/zq4030Isup2.hkl

checkCIF report

Computing details top

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO (Rigaku, 2015); data reduction: RAPID-AUTO (Rigaku, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg, 2018); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015b) and publCIF (Westrip, 2010).

trans-Bis[2-(aminomethyl)pyridine-κ²N,N']platinum(II)] bis(hexafluoridophosphate) top

Crystal data top

[Pt(C₆H₈N₂)₂](PF₆)₂	Z = 1
M_r = 701.32	F(000) = 332
Triclinic, P1	D_x = 2.377 Mg m⁻³
a = 7.3011 (3) Å	Mo Kα radiation, λ = 0.71075 Å
b = 8.3055 (3) Å	Cell parameters from 13361 reflections
c = 9.2821 (3) Å	θ = 2.5–32.6°
α = 64.226 (4)°	µ = 7.44 mm⁻¹
β = 75.212 (5)°	T = 296 K
γ = 84.540 (6)°	Needle, colourless
V = 489.99 (4) Å³	0.41 × 0.29 × 0.12 mm

Data collection top

Rigaku R-AXIS RAPID imaging-plate diffractometer	3484 independent reflections
Radiation source: X-ray sealed tube	3484 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.059
Detector resolution: 10.00 pixels mm^-1	θ_max = 32.6°, θ_min = 2.5°
ω scans	h = −11→10
Absorption correction: integration (NUMABS; Rigaku, 1999)	k = −12→12
T_min = 0.206, T_max = 0.508	l = −14→14
12933 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.028	H-atom parameters constrained
wR(F²) = 0.067	w = 1/[σ²(F_o²) + (0.0395P)²] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
3484 reflections	Δρ_max = 1.92 e Å⁻³
180 parameters	Δρ_min = −1.55 e Å⁻³
48 restraints	Extinction correction: (SHELXL2014; Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: heavy-atom method	Extinction coefficient: 0.038 (3)

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Pt	0.0000	0.5000	0.5000	0.03263 (7)
N1	0.1202 (5)	0.6204 (5)	0.2528 (4)	0.0488 (7)
H1A	0.0691	0.5740	0.2015	0.059*
H1B	0.0954	0.7367	0.2141	0.059*
N2	0.2490 (4)	0.3730 (4)	0.4965 (3)	0.0375 (5)
C1	0.3271 (6)	0.5969 (6)	0.2169 (5)	0.0525 (8)
H1C	0.3901	0.7028	0.2015	0.063*
H1D	0.3682	0.5818	0.1155	0.063*
C2	0.3812 (5)	0.4376 (5)	0.3542 (4)	0.0416 (6)
C3	0.5584 (6)	0.3611 (7)	0.3380 (6)	0.0555 (9)
H3	0.6484	0.4074	0.2382	0.067*
C4	0.5998 (6)	0.2157 (7)	0.4716 (7)	0.0608 (10)
H4	0.7185	0.1640	0.4638	0.073*
C5	0.4624 (7)	0.1487 (6)	0.6161 (7)	0.0582 (10)
H5	0.4870	0.0500	0.7072	0.070*
C6	0.2876 (6)	0.2284 (5)	0.6259 (5)	0.0489 (7)
H6	0.1946	0.1814	0.7237	0.059*
P	0.13393 (16)	0.17834 (14)	0.13320 (13)	0.04854 (19)
F1	0.3338 (7)	0.2085 (8)	0.1472 (8)	0.1137 (18)
F3	−0.0705 (8)	0.1541 (9)	0.1136 (8)	0.132 (3)
F2	0.1733 (10)	0.3286 (9)	−0.0505 (7)	0.096 (2)	0.744 (6)
F4	0.0336 (12)	0.3072 (11)	0.2050 (11)	0.115 (2)	0.744 (6)
F5	0.0933 (13)	0.0057 (10)	0.2996 (9)	0.118 (3)	0.744 (6)
F6	0.2280 (17)	0.0422 (11)	0.0581 (12)	0.135 (3)	0.744 (6)
F2B	0.131 (3)	0.399 (3)	0.070 (3)	0.107 (4)	0.256 (6)
F4B	0.076 (4)	0.167 (4)	0.313 (3)	0.115 (4)	0.256 (6)
F5B	0.161 (4)	−0.014 (3)	0.182 (4)	0.114 (4)	0.256 (6)
F6B	0.199 (4)	0.222 (4)	−0.047 (3)	0.110 (4)	0.256 (6)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Pt	0.03905 (9)	0.02788 (9)	0.02934 (8)	0.00042 (5)	−0.00823 (5)	−0.01065 (5)
N1	0.0496 (14)	0.0518 (17)	0.0335 (12)	0.0053 (13)	−0.0089 (11)	−0.0093 (11)
N2	0.0410 (11)	0.0324 (11)	0.0383 (12)	0.0031 (9)	−0.0117 (10)	−0.0137 (9)
C1	0.0476 (16)	0.053 (2)	0.0392 (16)	−0.0015 (15)	−0.0034 (13)	−0.0073 (14)
C2	0.0415 (13)	0.0400 (15)	0.0424 (15)	−0.0001 (11)	−0.0075 (12)	−0.0178 (12)
C3	0.0430 (16)	0.060 (2)	0.061 (2)	0.0034 (16)	−0.0062 (16)	−0.028 (2)
C4	0.0504 (18)	0.059 (2)	0.077 (3)	0.0162 (17)	−0.019 (2)	−0.033 (2)
C5	0.058 (2)	0.046 (2)	0.066 (3)	0.0142 (17)	−0.0238 (19)	−0.0179 (18)
C6	0.0517 (16)	0.0405 (16)	0.0461 (17)	0.0085 (14)	−0.0153 (14)	−0.0104 (13)
P	0.0556 (5)	0.0396 (4)	0.0434 (4)	0.0051 (4)	−0.0151 (4)	−0.0104 (3)
F1	0.081 (2)	0.114 (4)	0.137 (5)	−0.003 (2)	−0.057 (3)	−0.028 (3)
F3	0.102 (3)	0.126 (5)	0.136 (5)	−0.032 (3)	−0.067 (3)	0.001 (3)
F2	0.103 (4)	0.078 (3)	0.063 (3)	−0.004 (3)	−0.022 (3)	0.011 (3)
F4	0.131 (5)	0.106 (4)	0.117 (5)	0.030 (4)	−0.012 (4)	−0.072 (4)
F5	0.143 (5)	0.090 (4)	0.071 (3)	−0.021 (4)	−0.043 (3)	0.024 (3)
F6	0.197 (7)	0.089 (4)	0.118 (5)	0.038 (4)	−0.019 (5)	−0.060 (4)
F2B	0.125 (7)	0.072 (6)	0.108 (7)	0.012 (6)	−0.025 (6)	−0.027 (6)
F4B	0.146 (7)	0.117 (7)	0.074 (6)	0.001 (7)	−0.018 (6)	−0.038 (6)
F5B	0.165 (8)	0.067 (6)	0.099 (7)	0.009 (6)	−0.038 (7)	−0.022 (6)
F6B	0.154 (8)	0.099 (7)	0.071 (6)	0.005 (7)	−0.027 (6)	−0.032 (6)

Geometric parameters (Å, º) top

Pt—N2ⁱ	2.013 (3)	C4—C5	1.373 (8)
Pt—N2	2.013 (3)	C4—H4	0.9300
Pt—N1	2.044 (3)	C5—C6	1.382 (6)
Pt—N1ⁱ	2.044 (3)	C5—H5	0.9300
N1—C1	1.475 (5)	C6—H6	0.9300
N1—H1A	0.8900	P—F5B	1.46 (2)
N1—H1B	0.8900	P—F6B	1.50 (2)
N2—C2	1.340 (4)	P—F4	1.532 (6)
N2—C6	1.349 (4)	P—F1	1.551 (4)
C1—C2	1.491 (5)	P—F5	1.565 (5)
C1—H1C	0.9700	P—F4B	1.58 (2)
C1—H1D	0.9700	P—F2	1.586 (5)
C2—C3	1.388 (5)	P—F3	1.590 (5)
C3—C4	1.381 (7)	P—F6	1.590 (7)
C3—H3	0.9300	P—F2B	1.66 (2)

N2ⁱ—Pt—N2	180.0	N2—C6—C5	121.3 (4)
N2ⁱ—Pt—N1	99.33 (12)	N2—C6—H6	119.3
N2—Pt—N1	80.67 (12)	C5—C6—H6	119.3
N2ⁱ—Pt—N1ⁱ	80.67 (12)	F5B—P—F6B	92.5 (15)
N2—Pt—N1ⁱ	99.33 (12)	F5B—P—F1	93.4 (12)
N1—Pt—N1ⁱ	180.0	F6B—P—F1	93.6 (11)
C1—N1—Pt	111.7 (2)	F4—P—F1	95.5 (5)
C1—N1—H1A	109.3	F4—P—F5	96.1 (5)
Pt—N1—H1A	109.3	F1—P—F5	93.4 (4)
C1—N1—H1B	109.3	F5B—P—F4B	96.4 (15)
Pt—N1—H1B	109.3	F6B—P—F4B	170.4 (15)
H1A—N1—H1B	107.9	F1—P—F4B	82.2 (10)
C2—N2—C6	119.3 (3)	F4—P—F2	93.1 (5)
C2—N2—Pt	116.6 (2)	F1—P—F2	91.2 (3)
C6—N2—Pt	124.2 (2)	F5—P—F2	169.3 (5)
N1—C1—C2	110.6 (3)	F5B—P—F3	88.2 (12)
N1—C1—H1C	109.5	F6B—P—F3	85.2 (11)
C2—C1—H1C	109.5	F4—P—F3	84.0 (5)
N1—C1—H1D	109.5	F1—P—F3	178.0 (3)
C2—C1—H1D	109.5	F5—P—F3	88.5 (4)
H1C—C1—H1D	108.1	F4B—P—F3	98.8 (11)
N2—C2—C3	121.5 (4)	F2—P—F3	87.0 (3)
N2—C2—C1	116.0 (3)	F4—P—F6	177.1 (6)
C3—C2—C1	122.5 (4)	F1—P—F6	87.4 (5)
C4—C3—C2	119.3 (4)	F5—P—F6	83.6 (5)
C4—C3—H3	120.3	F2—P—F6	86.9 (5)
C2—C3—H3	120.3	F3—P—F6	93.2 (6)
C5—C4—C3	118.8 (4)	F5B—P—F2B	173.1 (15)
C5—C4—H4	120.6	F6B—P—F2B	84.9 (13)
C3—C4—H4	120.6	F1—P—F2B	80.5 (9)
C4—C5—C6	119.8 (4)	F4B—P—F2B	85.9 (13)
C4—C5—H5	120.1	F3—P—F2B	97.8 (9)
C6—C5—H5	120.1

Pt—N1—C1—C2	22.8 (5)	N2—C2—C3—C4	−0.3 (7)
C6—N2—C2—C3	−1.3 (5)	C1—C2—C3—C4	178.8 (4)
Pt—N2—C2—C3	179.6 (3)	C2—C3—C4—C5	1.2 (7)
C6—N2—C2—C1	179.6 (4)	C3—C4—C5—C6	−0.7 (8)
Pt—N2—C2—C1	0.5 (4)	C2—N2—C6—C5	1.9 (6)
N1—C1—C2—N2	−15.6 (5)	Pt—N2—C6—C5	−179.1 (3)
N1—C1—C2—C3	165.3 (4)	C4—C5—C6—N2	−0.9 (7)

Symmetry code: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···F2ⁱⁱ	0.89	2.40	3.080 (8)	133
N1—H1A···F4	0.89	2.24	2.971 (9)	139
N1—H1B···F6ⁱⁱⁱ	0.89	2.46	3.233 (10)	146
N1—H1A···F2B	0.89	2.22	2.98 (2)	143
N1—H1B···F5Bⁱⁱⁱ	0.89	2.05	2.84 (2)	148

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

Funding information

Funding for this research was provided by: JSPS KAKENHI (Coordination Asymmetry) (grant No. JP16H06509).

References

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