Coordination of bis-(pyrazol-1-yl)amine to palladium(II): influence of the co-ligands and counter-ions on the mol-ecular and crystal structures.

The structures of a series of complexes with general formula n[Pd(pza)X]Y·mH2O (n = 1, 2; X = Cl, Br, I, N3, NCS; Y = NO3, I, N3, [Pd(SCN)4]; m = 0, 0.5, 1) have been determined, where pza is the tridentate ligand bis-[2-(3,5-di-methyl-pyrazol-1-yl)eth-yl]amine, C14H23N5. In all complexes, {bis-[2-(3,5-di-methyl-pyrazol-1-yl-κN (2))eth-yl]amine-κN}chlorido-palladium nitrate, [Pd(pza)Cl]NO3, (1), {bis-[2-(3,5-di-methyl-pyrazol-1-yl-κN (2))eth-yl]amine-κN}bromido-palladium nitrate, [Pd(pza)Br]NO3, (2), {bis-[2-(3,5-di-methyl-pyrazol-1-yl-κN (2))eth-yl]amine-κN}iodido-palladium iodide hemihydrate, [Pd(pza)I]I·0.5H2O, (3), azido{bis-[2-(3,5-di-methyl-pyrazol-1-yl-κN (2))eth-yl]amine-κN}palladium azide monohydrate, [Pd(pza)N3]N3·H2O, (4), and bis-[{bis-[2-(3,5-di-methyl-pyrazol-1-yl-κN (2))eth-yl]amine-κN}(thio-cyanato-κN)palladium] tetra-kis-(thio-cyanato-κS)palladate, [Pd(pza)NCS]2[Pd(SCN)4], (5), the [Pd(pza)X](+) complex cation displays a square-planar coordination geometry, and the pza ligand is twisted, approximating twofold rotation symmetry. Although the pza ligand is found with the same conformation along the series, the dihedral angle between pyrazole rings depends on the co-ligand X. This angle span the range 79.0 (3)-88.6 (1)° for the studied complexes. In (3), two complex cations, two I(-) anions and one water mol-ecule of crystallization are present in the asymmetric unit. In (5), the central amine group of pza is disordered over two positions [occupancy ratio 0.770 (18):0.230 (18)]. The complex [Pd(SCN)4](2-) anion of this compound exhibits inversion symmetry and shows the Pd(2+) transition metal cation likewise in a square-planar coordination environment. Compound (5) is also a rare occurrence of a non-polymeric compound in which the pseudohalide ligand NCS(-) behaves both as thio-cyanate and iso-thio-cyanate, i.e. is coordinating either through the N atom (in the cation) or the S atom (in the anion).

Chemical context

The coordination chemistry of transition metals having a d 8 shell is clearly dominated by the square-planar geometry, which gives strong crystal field stabilization, because filled orbitals d z2 and degenerated orbitals (d xz d yz) do not inter­act directly with orbitals of the ligands. This holds true for group 10 metal complexes, for which the tetra­hedral geometry is considered as an oddity (Alvarez et al., 2005 ▸).

We synthesized a series of such square-planar complexes, with general formula n[Pd(pza)X]Y·mH2O, in which pza is the tridentate ligand bis-[2-(3,5-di­methyl­pyrazol-1-yl)eth­yl]amine, and X, Y are halide, pseudohalide, nitrate, or a complex anion. This series was first considered within a larger project related to a systematic study of modifications of cis-platin, obtained through the substitution of NH3 ligands by N-heterocyclic systems, like imidazole- and pyrazole-based ligands. The PdII synthetic chemistry may be easily transferred to PtII, with the advantage that PdII starting materials are somewhat cheaper than their PtII analogues. On the other hand, regarding the chemical crystallography, PdII complexes are almost always isostructural to their PtII analogues. Finally, any new PdII complex is also of potential inter­est for studies about the fundamental aspects of the catalysis of the Heck reaction type.

We thus focused our efforts on the crystallographic characterization of the PdII complexes obtained as single crystals, with the hope of rationalizing the effect of the co-ligand X and counter-ion Y on the mol­ecular and crystal structures of the complex [Pd(pza)X]+ cations. An earlier report of the crystal structure of the starting material, [Pd(pza)Cl]Cl·2H2O has been given (Mendoza et al., 2006 ▸), and we now report on the characterization of [Pd(pza)Cl]NO3 (1), [Pd(pza)Br]NO3 (2), [Pd(pza)I]I·0.5(H2O) (3), [Pd(pza)N3]N3·H2O (4), and 2[Pd(pza)NCS][Pd(SCN)4] (5).

Structural commentary: mol­ecular and crystal structures

Complex (1) is a result of the substitution of the counter-ion Y = Cl− in the starting material, i.e. in the dihydrate [Pd(pza)Cl]Cl·2H2O by a nitrate, but crystallizes as an anhydrous species, [Pd(pza)Cl]NO3 (Fig. 1 ▸). As expected, the square-planar coordination of the metal cation is retained, and the conformation of the pza ligand is not affected by the counter-ion substitution. The cation conformation may be characterized by the dihedral angle between the pyrazole mean planes, 85.1 (3)° versus 87.62 (11)° in the chloride salt (Mendoza et al., 2006 ▸). A least-squares fit between the [Pd(pza)Cl]+ cations in the chloride and nitrate salts gives an r.m.s. deviation of 0.124 Å. However, the crystal structures are different because the water mol­ecules in the chloride dihydrate are determinant for the supra­molecular arrangement through hydrogen-bonding and inter­molecular contacts. In (1), the nitrate ion inter­acts with the central amine group of the pza ligand, with a N10—H10⋯O1 separation of 1.98 Å. Other inter-ion contacts beyond the asymmetric unit are unexceptional, and the observed crystal structure is basically a consequence of Coulombic inter­actions rather than hydrogen bonds (Table 1 ▸).

Figure 1

View of the mol­ecular structure of complex (1), corresponding to X = Cl− and Y = NO3 −, with displacement ellipsoids for non-H atoms drawn at the 30% probability level. The inset is an overlay (Mercury; Macrae et al., 2008 ▸) of the cations in (1) and (2), in which X = Br−.

Table 1

Hydrogen-bond geometry (, ) for (1)

DHA	DH	HA	D A	DHA
C4H4AN20i	0.93	2.66	3.510(10)	153
C7H7CCl1	0.96	2.81	3.410(10)	121
C8H8AO3ii	0.97	2.28	3.222(10)	163
N10H10N20	0.90	2.57	3.453(10)	167
N10H10O1	0.90	1.98	2.857(9)	164
N10H10O2	0.90	2.45	3.186(10)	140
C14H14ACl1iii	0.93	2.82	3.629(9)	146
C16H16AO1iv	0.96	2.64	3.572(12)	164
C17H17AO3ii	0.96	2.53	3.491(12)	175
C17H17CCl1	0.96	2.79	3.367(10)	119
C18H18AO2	0.97	2.51	3.364(11)	146
C18H18BO1iv	0.97	2.61	3.428(11)	142
C19H19AO3iv	0.97	2.47	3.112(11)	124

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

Complex (2), with X = Br− and Y = NO3 − is isostructural with the X = Cl− analogue (1). However, a slight relaxation of the folded pza ligand is observed, with a dihedral angle between pyrazole rings of 83.6 (2)°. An overlay between cations in (1) and (2) gives a small deviation of 0.049 Å (Fig. 1 ▸, inset). The nitrate anion inter­acts with the complex cation in (2) with a distance N10—H10⋯O1 = 1.98 Å (Table 2 ▸). Thus, the nature of the halogen co-ligand X in [Pd(pza)X]NO3 seems to be unimportant for the resulting crystal structure.

Table 2

Hydrogen-bond geometry (, ) for (2)

DHA	DH	HA	D A	DHA
C4H4AN20i	0.93	2.66	3.540(7)	159
C7H7CBr1	0.96	3.06	3.500(8)	110
C8H8AO3ii	0.97	2.30	3.219(9)	157
N10H10N20	0.90	2.54	3.427(6)	169
N10H10O1	0.90	1.98	2.857(7)	166
N10H10O2	0.90	2.43	3.181(8)	142
C14H14ABr1iii	0.93	2.88	3.687(6)	146
C16H16AO1iv	0.96	2.65	3.511(10)	150
C17H17AO3ii	0.96	2.55	3.485(10)	164
C17H17CBr1	0.96	2.98	3.459(8)	112
C18H18AO2	0.97	2.52	3.358(9)	144
C18H18BO1iv	0.97	2.65	3.468(8)	142
C19H19BO3iv	0.97	2.47	3.099(9)	122

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

Complex (3), built up with X = Y = iodide, crystallized as a hemihydrate, with two cation complexes and two free iodide ions in the asymmetric unit (Fig. 2 ▸). The square-planar geometry of PdII is retained, as well as the pza conformation. However, the relaxation of folding, observed with X = Br− in compound (2), is amplified with X = I−: the angle between the pyrazole rings is now 79.0 (3) and 83.3 (3)°, for the Pd1 and Pd2 cations, respectively. There seems to be a regular trend for [Pd(pza)X]+ cations: the smaller the ionic radius of the co-ligand X, the closer the angle between the pyrazole rings is to 90°. A possible rationalization of this observation is that methyl groups substituting pyrazole rings at position 3 inter­act with the co-ligand X. This destabilizing steric inter­action favors the twisting of pza, which in general adopts a non-crystallographic twofold rotation symmetry. However, the large iodide anion forces the separation between methyl groups, compared to the small chloride ion. In order to keep the coordination geometry around PdII as planar as possible, the heterocycles in pza then make a slight rotation motion, which is reflected in the deviation from orthogonality of these terminal rings. In other words, the combined twisting and folding motions of the pza ligand lead to as planar as possible a coordination environment for PdII. Counter-ions Y and lattice water mol­ecules have only slight influences, if any, on the cation conformation. In the case of (3), the water mol­ecule behaves both as a donor and acceptor group for hydrogen bonding. O—H⋯I bonds are formed with the non-coordin­ating iodide anions, and the central amine group of pza forms a N—H⋯O bond with the same water mol­ecule (Table 3 ▸). However, as for previous complexes (1) and (2), no extended supra­molecular structures are formed in the crystal.

Figure 2

View of the mol­ecular structure of complex (3), corresponding to X = Y = I−, with displacement ellipsoids for non-H atoms drawn at the 30% probability level.

Table 3

Hydrogen-bond geometry (, ) for (3)

DHA	DH	HA	D A	DHA
O1H1I3	0.85	2.68	3.497(7)	161
O1H2I4	0.85	2.66	3.443(10)	155
N10H10AI3i	0.90	2.94	3.653(6)	137
N30H30AO1ii	0.90	2.22	3.011(9)	146
N30H30AI4ii	0.90	3.30	3.853(6)	122

Symmetry codes: (i) ; (ii) .

Using the pseudohalide X = Y = azide, compound (4) was crystallized as an hydrate, [Pd(pza)N3]N3·H2O (Fig. 3 ▸). The nitro­gen atoms in the coordinating N3 − ligand are not steric­ally demanding as the iodide ion in (3) and, as a consequence, the pyrazole rings come back in a more orthogonal arrangement, identical to that observed in [Pd(pza)Cl]+. The dihedral angle between pyrazole rings is 87.3 (1)° in (4). The strongest hydrogen bond is found between the amine group of pza and the free azide ion, the N10—H10⋯N32 separation being 1.95 Å and the angle for the contact 171° (Table 4 ▸).

Figure 3

View of the mol­ecular structure of complex (4), corresponding to X = Y = N3 −, with displacement ellipsoids for non-H atoms drawn at the 30% probability level.

Table 4

Hydrogen-bond geometry (, ) for (4)

DHA	DH	HA	D A	DHA
N10H10N32	0.90	1.95	2.838(11)	171
N10H10N31	0.90	2.66	3.460(13)	148
O1H11N32i	0.84	2.67	3.295(19)	132
O1H12N30	0.85	2.38	3.08(2)	140

Symmetry code: (i) .

Finally, in the fifth compound (5), the counter-ion Y is a complex anion, namely [Pd(SCN)4]2−. The formula for (5) is 2[Pd(pza)NCS][Pd(SCN)4], and the anion is located about an inversion centre, while the cation is in a general position (Fig. 4 ▸). The pza ligand in [Pd(pza)NCS]+, in contrast to previous compounds, has the amine group N10 disordered over two positions, N10A and N10B, with occupancies 0.770 (18) and 0.230 (18), respectively. The same type of disorder was previously reported for an AuIII complex (Segapelo et al., 2011 ▸). In spite of this disorder, the general conformation of pza is identical to that observed in compounds (1)–(4), approximating the non-crystallographic twofold rotation symmetry. The co-ligand X = NCS− coordin­ates through its N atom, and the local environment of the metal is very similar to that resulting from azide coord­in­ation in complex (4). The dihedral angle between pyrazole rings should thus be close to 90°. The actual value is 88.6 (1)°. The anion [Pd(SCN)4]2− is also square-planar, but with the ligands coordinating in a κS-fashion, while in the cation, the NCS ligand is bound in a κN-fashion to the metal cation. If complexes with bridging thio­cyanate ligands are not considered, very few structures are known in which the ambidentate ligand NCS− is bonded in two modes (κS- and κN-) to the same transition metal. In the case of PdII, classified as a soft acid in the Pearson’s HSAB concept, the soft base SCN− should have a preference for the κS-coordination. Apparently, only a few non-polymeric crystal structures have been reported including both coordination modes of SCN− to this metal (e.g. Paviglianiti et al., 1989 ▸; Chang et al., 2005 ▸). In the crystal structure, weak hydrogen bonds between the disordered amino group and the NCS groups of neighbouring cations and anions are observed (Table 5 ▸).

Figure 4

View of the mol­ecular structure of complex (5), corresponding to X = NCS− and Y = [Pd(SCN)4]2−, with displacement ellipsoids for non-H atoms at the 30% probability level. Only one position for the disordered amine group in the cation has been retained (N10A). In the anion, unlabelled atoms are generated by symmetry code (−x + 1, −y + 2, −z + 2).

Table 5

Hydrogen-bond geometry (, ) for (5)

DHA	DH	HA	D A	DHA
N10AH10AN24i	0.90	2.01	2.889(9)	166
N10BH10BS1ii	0.90	2.71	3.52(2)	151

Symmetry codes: (i) ; (ii) .

Database survey

The ligand pza has been widely used in coordination chemistry. The current release of the CSD (Version 5.35 with all updates; Groom & Allen, 2014 ▸) affords 39 entries distributed over 18 articles. With PdII, two structures are reported to date, which are pseudopolymorphs with X = Y = Cl− (Mendoza et al., 2006 ▸; Guzei et al., 2010 ▸). Other transition metals have been coordinated by pza and structures are available for CoII (van Berkel et al., 1994 ▸; Massoud et al., 2012a ▸, 2013 ▸), NiII (Ajellal et al., 2006 ▸; Massoud et al., 2012a ▸, 2013 ▸), CuII (van Berkel et al., 1994 ▸; Martens et al., 1995 ▸; Kim et al., 2000 ▸; Monzani et al., 2000 ▸; Riklin et al., 2001 ▸; Massoud et al., 2012a ▸,b ▸, 2013 ▸), ZnII (Burth & Vahrenkamp, 1998 ▸; Lian et al., 2007a ▸; Lee et al., 2007 ▸; Massoud et al., 2013 ▸), CdII (Griffith et al., 1987 ▸; Massoud et al., 2013 ▸), ReI (Alves et al., 2002 ▸) and AuIII (Segapelo et al., 2011 ▸). The pza ligand generally behaves as a tridentate ligand, with exceptions for some ZnII compounds, in which one pyrazole ring is not coordinating to the metal (Burth & Vahrenkamp, 1998 ▸; Lian et al., 2007a ▸; Lee et al., 2007 ▸). Few complexes have also been prepared with s- and p-metals, viz. LiI (Lian et al., 2007a ▸), MgII (Lian et al., 2007b ▸), and AlIII (Lian et al., 2007a ▸).

The conformation observed for pza is determined by the coordination number of the metal centre. For example, hexa-coordinated transition metals like NiII or CdII favor the facial coordination of pza, which is then found in a folded conformation, while coordination numbers 5 and 4 promote some defolding. The ligand pza with the dihedral angle between pyrazole rings very close to 0° has been observed in CoII complexes (Massoud et al., 2012a ▸, 2013 ▸). A conformation for pza close to that observed in (1)–(5) has been reported with MgII (Lian et al., 2007b ▸) and AuIII (Segapelo et al., 2011 ▸).

Synthesis and crystallization

Complexes (1)–(5) were synthesized starting from [Pd(pza)Cl]Cl·2H2O (Mendoza et al., 2006 ▸), by substitution of co-ligands and counter-ions, as depicted in Fig. 5 ▸.

Figure 5

General synthetic scheme for complexes (1)–(5).

Synthesis of (1). [Pd(pza)Cl]Cl·2H2O (1 mmol) was dissolved in CH3CN, and a solution of AgNO3 (1 mmol in CH3CN) was added slowly. The mixture was stirred for 1 h at room temperature. After elimination by filtration of the white precipitate of AgCl, the mixture was further stirred for 1 h. Evaporation of the solvent afforded complex (1) as a brown–yellow solid, in 82% yield, and crystals were obtained by recrystallization from CH3CN.

Synthesis of (2). [Pd(pza)Cl]Cl·2H2O (1 mmol) was dissolved in CH3CN, and a solution of AgNO3 (2 mmol in CH3CN) was added slowly. The mixture was stirred for 2 h at room temperature, and the precipitated AgCl was removed by filtration. An aqueous solution of NaBr (1 mmol) was then added, and NaNO3 precipitates, which was removed by filtration. The solution was further stirred for 5 h. Evaporation of the solvent afforded complex (2) as a yellow solid, in 76% yield, and crystals were obtained by recrystallization from CH3CN.

Synthesis of (3). [Pd(pza)Cl]Cl·2H2O (1 mmol) was dissolved in CH3CN (5 ml) and a solution of 2 mmol of NaBF4 in CH3CN was added slowly. After elimination of NaCl by filtration, a solution of 2 mmol of NEt4I in CH3CN was added slowly, and the mixture, which turned red, was stirred for 6 h at room temperature. Evaporation of the solvent afforded complex (3) as a red solid, in 82% yield, and crystals were obtained by recrystallization from CH3CN. Alternatively, complex (3) may be obtained in 89% yield by reacting an aqueous solution of [Pd(pza)Cl]Cl·2H2O (1 mmol) and NaI (2 mmol) for 6 h at room temperature.

Synthesis of (4). [Pd(pza)Cl]Cl·2H2O (1 mmol) was dissolved in CH3CN. A solution of NaN3 (2 mmol, CH3CN/H2O mixture 4:1, v/v) was added slowly. The formed precipitate of NaCl was eliminated by filtration, and the mixture was further stirred at room temperature for 10 h. Evaporation of the solvent afforded complex (4) as a yellow solid, in 61% yield, and crystals were obtained by recrystallization from CH3CN.

Synthesis of (5). [Pd(pza)Cl]Cl·2H2O (1 mmol) was dissolved in H2O, and an aqueous solution of 2 mmol of KNCS was added slowly. The mixture was stirred for 10 h at room temperature. The formed pink solid, (5), was separated by filtration and dried in reduced pressure at 313 K. Yield: 48%. Crystals were obtained by recrystallization from a mixture of CH3CN and CH2Cl2 (2:1, v/v).

Refinement

Crystal data, data collection and structure refinement details for (1)–(5) are summarized in Table 6 ▸. Data collection and refinement are routine works, except for a positional disorder found in (5) for sites N10A/N10B, for which the s.o.f. converged to 0.770 (18) and 0.230 (18), respectively. All H atoms bonded to C and N atoms were placed in calculated positions and refined as riding atoms, with fixed bond lengths of 0.93, 0.96, 0.97, and 0.90 Å for aromatic, methyl, methyl­ene, and amine groups, respectively. In (3) and (4), H atoms for water mol­ecules were found in difference maps, and first refined with free coordinates and restrained distances O—H = 0.85 (2) and H⋯H = 1.34 (4) Å. In the final cycles, water H atoms were fixed and refined as riding atoms. Isotropic displacement parameters for all H atoms were calculated as U iso(H) = xU eq(carrier atom), with x = 1.2 (methyl­ene, aromatic, and amine groups) or x = 1.5 (methyl and water).

Table 6

Experimental details

	(1)	(2)	(3)	(4)	(5)
Crystal data
Chemical formula	[PdCl(C14H23N5)]NO3	[PdBr(C14H23N5)]NO3	[PdI(C14H2N5)]I0.5H2O	[Pd(N3)(C14H23N5)]N3H2O	[Pd(NCS)(C14H23N5)]2[Pd(NCS)4]
M r	465.23	509.69	630.58	469.85	1190.43
Crystal system, space group	Monoclinic, P21/n	Monoclinic, P21/n	Triclinic, P	Monoclinic, P21/c	Triclinic, P
Temperature (K)	298	298	299	296	298
a, b, c ()	11.046(2), 12.2941(15), 14.0978(16)	10.934(6), 12.443(4), 14.112(6)	12.013(4), 12.089(4), 15.162(5)	8.132(3), 22.851(5), 11.372(3)	9.0286(17), 10.532(2), 13.066(3)
, , ()	90, 94.740(16), 90	90, 94.76(4), 90	106.17(2), 97.34(3), 106.79(3)	90, 109.03(2), 90	94.838(14), 100.947(12), 103.989(13)
V (3)	1907.9(5)	1913.4(14)	1972.0(11)	1997.8(10)	1172.5(4)
Z	4	4	4	4	1
Radiation type	Mo K	Mo K	Mo K	Mo K	Mo K
(mm1)	1.14	3.08	4.08	0.96	1.45
Crystal size (mm)	0.40 0.12 0.10	0.60 0.40 0.18	0.20 0.15 0.04	0.50 0.40 0.40	0.40 0.40 0.12
Data collection
Diffractometer	Siemens P4	Siemens P4	Siemens P4	Siemens P4	Siemens P4
Absorption correction	scan (XSCANS; Siemens, 1996 ▸)	scan (XSCANS; Siemens, 1996 ▸)	scan (XSCANS; Siemens, 1996 ▸)	scan (XSCANS; Siemens, 1996 ▸)	scan (XSCANS; Siemens, 1996 ▸)
T min, T max	0.469, 0.517	0.206, 0.352	0.446, 0.523	0.266, 0.366	0.256, 0.378
No. of measured, independent and observed [I > 2(I)] reflections	4513, 3372, 2110	12224, 4962, 3329	8975, 6835, 4559	8431, 4032, 3528	8889, 5367, 4874
R int	0.044	0.080	0.043	0.056	0.038
(sin /)max (1)	0.596	0.677	0.595	0.623	0.650
Refinement
R[F 2 > 2(F 2)], wR(F 2), S	0.060, 0.158, 1.05	0.051, 0.148, 1.05	0.040, 0.101, 1.03	0.036, 0.097, 1.08	0.039, 0.107, 1.06
No. of reflections	3372	4962	6835	4032	5367
No. of parameters	230	231	414	248	282
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained
max, min (e 3)	1.45, 1.11	1.10, 1.01	0.85, 1.04	0.55, 1.04	0.83, 1.06

Computer programs: XSCANS (Siemens, 1996 ▸), SHELXS2014, SHELXL2014 and SHELXTL (Sheldrick, 2008 ▸) and Mercury (Macrae et al., 2008 ▸).

Crystal structure: contains datablock(s) 1, 2, 3, 4, 5, global. DOI: 10.1107/S205698901402595X/wm5076sup1.cif

Structure factors: contains datablock(s) 1. DOI: 10.1107/S205698901402595X/wm50761sup2.hkl

Structure factors: contains datablock(s) 2. DOI: 10.1107/S205698901402595X/wm50762sup3.hkl

Structure factors: contains datablock(s) 3. DOI: 10.1107/S205698901402595X/wm50763sup4.hkl

Structure factors: contains datablock(s) 4. DOI: 10.1107/S205698901402595X/wm50764sup5.hkl

Structure factors: contains datablock(s) 5. DOI: 10.1107/S205698901402595X/wm50765sup6.hkl

CCDC references: 1036262, 1036261, 1036260, 1036259, 1036258

Additional supporting information: crystallographic information; 3D view; checkCIF report

[Pd(NCS)(C14H23N5)]2[Pd(NCS)4]	Z = 1
Mr = 1190.43	F(000) = 596
Triclinic, P1	Dx = 1.686 Mg m−3
a = 9.0286 (17) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.532 (2) Å	Cell parameters from 75 reflections
c = 13.066 (3) Å	θ = 4.7–12.4°
α = 94.838 (14)°	µ = 1.45 mm−1
β = 100.947 (12)°	T = 298 K
γ = 103.989 (13)°	Irregular Plate, pink
V = 1172.5 (4) Å3	0.40 × 0.40 × 0.12 mm

Siemens P4 diffractometer	4874 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube, FN4	Rint = 0.038
Graphite monochromator	θmax = 27.5°, θmin = 2.0°
2θ/ω scans	h = −11→6
Absorption correction: ψ scan (XSCANS; Siemens, 1996)	k = −13→13
Tmin = 0.256, Tmax = 0.378	l = −16→16
8889 measured reflections	3 standard reflections every 97 reflections
5367 independent reflections	intensity decay: 1%

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0569P)2 + 1.1014P] where P = (Fo2 + 2Fc2)/3
5367 reflections	(Δ/σ)max < 0.001
282 parameters	Δρmax = 0.83 e Å−3
0 restraints	Δρmin = −1.06 e Å−3
0 constraints

	x	y	z	Uiso*/Ueq	Occ. (<1)
Pd1	0.36057 (3)	0.61306 (2)	0.33358 (2)	0.03862 (9)
S1	0.88007 (13)	0.60961 (16)	0.47191 (8)	0.0735 (4)
N1	0.3690 (3)	0.4656 (3)	0.2291 (2)	0.0420 (6)
N2	0.2424 (3)	0.3584 (3)	0.2003 (2)	0.0453 (6)
C3	0.2603 (4)	0.2765 (4)	0.1225 (3)	0.0526 (8)
C4	0.4009 (5)	0.3330 (4)	0.0994 (3)	0.0545 (9)
H4A	0.4443	0.2987	0.0479	0.065*
C5	0.4667 (4)	0.4500 (4)	0.1663 (2)	0.0448 (7)
C6	0.1425 (6)	0.1487 (5)	0.0757 (4)	0.0814 (15)
H6A	0.0469	0.1661	0.0415	0.122*
H6B	0.1228	0.0957	0.1304	0.122*
H6C	0.1822	0.1024	0.0253	0.122*
C7	0.6181 (5)	0.5472 (5)	0.1716 (3)	0.0610 (9)
H7A	0.6078	0.6349	0.1879	0.091*
H7B	0.6475	0.5390	0.1050	0.091*
H7C	0.6969	0.5308	0.2254	0.091*
C8	0.1152 (4)	0.3501 (4)	0.2545 (3)	0.0531 (8)
H8A	0.1555	0.3552	0.3295	0.064*
H8B	0.0391	0.2653	0.2308	0.064*
C9	0.0363 (4)	0.4580 (4)	0.2354 (3)	0.0564 (9)
H9A	−0.0338	0.4356	0.1666	0.068*	0.770 (18)
H9B	−0.0264	0.4637	0.2874	0.068*	0.770 (18)
H9C	0.0179	0.4648	0.1608	0.068*	0.230 (18)
H9D	−0.0650	0.4328	0.2538	0.068*	0.230 (18)
N10A	0.1465 (5)	0.5881 (4)	0.2405 (5)	0.0423 (14)	0.770 (18)
H10A	0.1658	0.5870	0.1754	0.051*	0.770 (18)
N10B	0.1157 (15)	0.5806 (14)	0.2894 (18)	0.041 (4)	0.230 (18)
H10B	0.0858	0.5793	0.3513	0.049*	0.230 (18)
N11	0.3365 (3)	0.7611 (3)	0.4311 (2)	0.0450 (6)
N12	0.2638 (3)	0.8493 (3)	0.3896 (2)	0.0490 (6)
C13	0.2571 (5)	0.9392 (4)	0.4656 (4)	0.0641 (11)
C14	0.3268 (6)	0.9078 (5)	0.5585 (4)	0.0698 (12)
H14A	0.3399	0.9534	0.6251	0.084*
C15	0.3743 (5)	0.7964 (4)	0.5356 (3)	0.0571 (9)
C16	0.1801 (7)	1.0477 (6)	0.4450 (6)	0.0965 (19)
H16A	0.2306	1.1016	0.3993	0.145*
H16B	0.1883	1.1009	0.5102	0.145*
H16C	0.0717	1.0105	0.4120	0.145*
C17	0.4503 (7)	0.7208 (6)	0.6096 (3)	0.0769 (13)
H17A	0.5170	0.6803	0.5766	0.115*
H17B	0.3717	0.6535	0.6288	0.115*
H17C	0.5115	0.7793	0.6716	0.115*
C18	0.1923 (5)	0.8273 (4)	0.2784 (3)	0.0552 (9)
H18A	0.2722	0.8288	0.2380	0.066*
H18B	0.1442	0.8981	0.2613	0.066*
C19	0.0713 (4)	0.6981 (4)	0.2488 (3)	0.0517 (8)
H19A	0.0083	0.6857	0.3014	0.062*	0.770 (18)
H19B	0.0028	0.6979	0.1818	0.062*	0.770 (18)
H19C	0.0421	0.6799	0.1726	0.062*	0.230 (18)
H19D	−0.0209	0.7072	0.2734	0.062*	0.230 (18)
N20	0.5799 (4)	0.6337 (3)	0.4077 (3)	0.0558 (8)
C21	0.7053 (4)	0.6233 (4)	0.4336 (3)	0.0517 (8)
Pd2	0.5000	1.0000	1.0000	0.03984 (10)
S22	0.27722 (13)	0.83780 (12)	0.91759 (10)	0.0736 (3)
C23	0.2457 (4)	0.7188 (5)	0.9922 (3)	0.0567 (9)
N24	0.2159 (6)	0.6323 (5)	1.0375 (3)	0.0849 (13)
S25	0.45759 (12)	1.11365 (12)	0.85705 (8)	0.0604 (3)
C26	0.2664 (5)	1.0806 (5)	0.8121 (3)	0.0617 (10)
N27	0.1366 (6)	1.0626 (6)	0.7789 (4)	0.1036 (18)

	U11	U22	U33	U12	U13	U23
Pd1	0.03258 (13)	0.04589 (15)	0.03637 (13)	0.01607 (10)	0.00092 (9)	−0.00186 (9)
S1	0.0489 (5)	0.1354 (11)	0.0481 (5)	0.0505 (6)	0.0069 (4)	0.0103 (6)
N1	0.0391 (13)	0.0488 (15)	0.0379 (12)	0.0161 (11)	0.0053 (10)	−0.0014 (11)
N2	0.0382 (13)	0.0543 (16)	0.0404 (13)	0.0122 (12)	0.0071 (11)	−0.0062 (11)
C3	0.0485 (18)	0.060 (2)	0.0478 (17)	0.0214 (16)	0.0059 (14)	−0.0103 (15)
C4	0.051 (2)	0.069 (2)	0.0476 (18)	0.0254 (18)	0.0139 (15)	−0.0029 (16)
C5	0.0432 (16)	0.0583 (19)	0.0394 (15)	0.0249 (15)	0.0095 (12)	0.0067 (13)
C6	0.069 (3)	0.077 (3)	0.085 (3)	0.005 (2)	0.021 (2)	−0.031 (3)
C7	0.053 (2)	0.071 (3)	0.066 (2)	0.0196 (19)	0.0231 (18)	0.0106 (19)
C8	0.0507 (19)	0.058 (2)	0.0485 (18)	0.0084 (16)	0.0190 (15)	−0.0036 (15)
C9	0.0334 (16)	0.070 (2)	0.062 (2)	0.0129 (15)	0.0098 (15)	−0.0085 (18)
N10A	0.0321 (19)	0.059 (2)	0.038 (3)	0.0197 (16)	0.0053 (18)	0.0015 (17)
N10B	0.025 (5)	0.064 (8)	0.037 (9)	0.017 (5)	0.010 (5)	0.000 (6)
N11	0.0449 (14)	0.0451 (15)	0.0455 (14)	0.0178 (12)	0.0061 (11)	−0.0001 (11)
N12	0.0422 (14)	0.0464 (15)	0.0599 (17)	0.0171 (12)	0.0089 (12)	0.0043 (13)
C13	0.051 (2)	0.046 (2)	0.091 (3)	0.0135 (16)	0.012 (2)	−0.0113 (19)
C14	0.071 (3)	0.066 (3)	0.065 (2)	0.017 (2)	0.012 (2)	−0.021 (2)
C15	0.062 (2)	0.055 (2)	0.0474 (18)	0.0104 (17)	0.0080 (16)	−0.0063 (15)
C16	0.085 (4)	0.062 (3)	0.142 (5)	0.037 (3)	0.014 (4)	−0.015 (3)
C17	0.093 (4)	0.085 (3)	0.045 (2)	0.022 (3)	0.001 (2)	0.005 (2)
C18	0.0502 (19)	0.065 (2)	0.062 (2)	0.0296 (17)	0.0175 (16)	0.0199 (18)
C19	0.0364 (16)	0.075 (2)	0.0500 (18)	0.0282 (16)	0.0056 (13)	0.0091 (16)
N20	0.0388 (15)	0.0595 (19)	0.0648 (19)	0.0215 (13)	−0.0024 (13)	−0.0102 (15)
C21	0.0473 (19)	0.065 (2)	0.0425 (16)	0.0237 (16)	0.0014 (14)	−0.0029 (15)
Pd2	0.02961 (16)	0.0489 (2)	0.04031 (18)	0.01548 (13)	0.00172 (12)	0.00076 (14)
S22	0.0517 (6)	0.0667 (7)	0.0806 (7)	0.0003 (5)	−0.0215 (5)	0.0161 (5)
C23	0.0440 (18)	0.070 (2)	0.0495 (19)	0.0088 (17)	0.0082 (15)	−0.0040 (17)
N24	0.085 (3)	0.096 (3)	0.057 (2)	−0.007 (2)	0.015 (2)	0.016 (2)
S25	0.0460 (5)	0.0790 (7)	0.0549 (5)	0.0166 (4)	0.0031 (4)	0.0192 (5)
C26	0.056 (2)	0.081 (3)	0.051 (2)	0.032 (2)	0.0013 (17)	0.0122 (19)
N27	0.062 (3)	0.153 (5)	0.103 (4)	0.046 (3)	−0.001 (2)	0.044 (4)

Pd1—N20	1.984 (3)	N10B—H10B	0.9000
Pd1—N1	2.005 (3)	N11—C15	1.340 (5)
Pd1—N11	2.009 (3)	N11—N12	1.353 (4)
Pd1—N10A	2.022 (4)	N12—C13	1.335 (5)
Pd1—N10B	2.111 (12)	N12—C18	1.447 (5)
S1—C21	1.607 (4)	C13—C14	1.362 (7)
N1—C5	1.342 (4)	C13—C16	1.493 (7)
N1—N2	1.365 (4)	C14—C15	1.372 (6)
N2—C3	1.336 (4)	C14—H14A	0.9300
N2—C8	1.449 (4)	C15—C17	1.478 (6)
C3—C4	1.366 (6)	C16—H16A	0.9600
C3—C6	1.496 (6)	C16—H16B	0.9600
C4—C5	1.379 (5)	C16—H16C	0.9600
C4—H4A	0.9300	C17—H17A	0.9600
C5—C7	1.482 (5)	C17—H17B	0.9600
C6—H6A	0.9600	C17—H17C	0.9600
C6—H6B	0.9600	C18—C19	1.493 (6)
C6—H6C	0.9600	C18—H18A	0.9700
C7—H7A	0.9600	C18—H18B	0.9700
C7—H7B	0.9600	C19—H19A	0.9700
C7—H7C	0.9600	C19—H19B	0.9700
C8—C9	1.494 (6)	C19—H19C	0.9700
C8—H8A	0.9700	C19—H19D	0.9700
C8—H8B	0.9700	N20—C21	1.153 (5)
C9—N10B	1.373 (14)	Pd2—S22	2.3085 (12)
C9—N10A	1.474 (6)	Pd2—S22i	2.3085 (12)
C9—H9A	0.9700	Pd2—S25	2.3227 (11)
C9—H9B	0.9700	Pd2—S25i	2.3227 (11)
C9—H9C	0.9700	S22—C23	1.656 (5)
C9—H9D	0.9700	C23—N24	1.133 (6)
N10A—C19	1.483 (5)	S25—C26	1.654 (4)
N10A—H10A	0.9000	C26—N27	1.133 (6)
N10B—C19	1.498 (15)
N20—Pd1—N1	91.68 (12)	C19—N10B—Pd1	111.8 (9)
N20—Pd1—N11	92.64 (12)	C9—N10B—H10B	103.3
N1—Pd1—N11	175.60 (11)	C19—N10B—H10B	103.3
N20—Pd1—N10A	172.5 (2)	Pd1—N10B—H10B	103.3
N1—Pd1—N10A	82.54 (18)	C15—N11—N12	106.7 (3)
N11—Pd1—N10A	93.08 (18)	C15—N11—Pd1	134.6 (3)
N20—Pd1—N10B	166.4 (7)	N12—N11—Pd1	118.6 (2)
N1—Pd1—N10B	94.8 (5)	C13—N12—N11	110.3 (3)
N11—Pd1—N10B	81.2 (5)	C13—N12—C18	129.9 (3)
C5—N1—N2	106.4 (3)	N11—N12—C18	119.4 (3)
C5—N1—Pd1	134.7 (3)	N12—C13—C14	107.0 (4)
N2—N1—Pd1	118.4 (2)	N12—C13—C16	123.0 (5)
C3—N2—N1	110.7 (3)	C14—C13—C16	129.9 (5)
C3—N2—C8	130.8 (3)	C13—C14—C15	107.3 (4)
N1—N2—C8	118.5 (3)	C13—C14—H14A	126.4
N2—C3—C4	106.7 (3)	C15—C14—H14A	126.4
N2—C3—C6	123.2 (4)	N11—C15—C14	108.7 (4)
C4—C3—C6	130.1 (3)	N11—C15—C17	123.2 (4)
C3—C4—C5	107.6 (3)	C14—C15—C17	128.1 (4)
C3—C4—H4A	126.2	C13—C16—H16A	109.5
C5—C4—H4A	126.2	C13—C16—H16B	109.5
N1—C5—C4	108.6 (3)	H16A—C16—H16B	109.5
N1—C5—C7	123.2 (3)	C13—C16—H16C	109.5
C4—C5—C7	128.2 (3)	H16A—C16—H16C	109.5
C3—C6—H6A	109.5	H16B—C16—H16C	109.5
C3—C6—H6B	109.5	C15—C17—H17A	109.5
H6A—C6—H6B	109.5	C15—C17—H17B	109.5
C3—C6—H6C	109.5	H17A—C17—H17B	109.5
H6A—C6—H6C	109.5	C15—C17—H17C	109.5
H6B—C6—H6C	109.5	H17A—C17—H17C	109.5
C5—C7—H7A	109.5	H17B—C17—H17C	109.5
C5—C7—H7B	109.5	N12—C18—C19	111.4 (3)
H7A—C7—H7B	109.5	N12—C18—H18A	109.4
C5—C7—H7C	109.5	C19—C18—H18A	109.4
H7A—C7—H7C	109.5	N12—C18—H18B	109.4
H7B—C7—H7C	109.5	C19—C18—H18B	109.4
N2—C8—C9	112.1 (3)	H18A—C18—H18B	108.0
N2—C8—H8A	109.2	N10A—C19—C18	110.4 (3)
C9—C8—H8A	109.2	C18—C19—N10B	116.8 (5)
N2—C8—H8B	109.2	N10A—C19—H19A	109.6
C9—C8—H8B	109.2	C18—C19—H19A	109.6
H8A—C8—H8B	107.9	N10A—C19—H19B	109.6
N10B—C9—C8	115.9 (6)	C18—C19—H19B	109.6
N10A—C9—C8	113.3 (3)	H19A—C19—H19B	108.1
N10A—C9—H9A	108.9	C18—C19—H19C	108.1
C8—C9—H9A	108.9	N10B—C19—H19C	108.1
N10A—C9—H9B	108.9	C18—C19—H19D	108.1
C8—C9—H9B	108.9	N10B—C19—H19D	108.1
H9A—C9—H9B	107.7	H19C—C19—H19D	107.3
N10B—C9—H9C	108.3	C21—N20—Pd1	164.8 (3)
C8—C9—H9C	108.3	N20—C21—S1	179.0 (4)
N10B—C9—H9D	108.3	S22—Pd2—S22i	180.0
C8—C9—H9D	108.3	S22—Pd2—S25	87.77 (4)
H9C—C9—H9D	107.4	S22i—Pd2—S25	92.23 (4)
C9—N10A—C19	112.4 (4)	S22—Pd2—S25i	92.23 (4)
C9—N10A—Pd1	115.1 (3)	S22i—Pd2—S25i	87.77 (4)
C19—N10A—Pd1	117.4 (3)	S25—Pd2—S25i	180.0
C9—N10A—H10A	103.2	C23—S22—Pd2	109.52 (14)
C19—N10A—H10A	103.2	N24—C23—S22	175.1 (4)
Pd1—N10A—H10A	103.2	C26—S25—Pd2	107.53 (16)
C9—N10B—C19	117.7 (11)	N27—C26—S25	176.9 (5)
C9—N10B—Pd1	115.0 (8)
C5—N1—N2—C3	0.8 (4)	C15—N11—N12—C13	0.6 (4)
Pd1—N1—N2—C3	173.4 (2)	Pd1—N11—N12—C13	179.3 (3)
C5—N1—N2—C8	−178.9 (3)	C15—N11—N12—C18	−172.6 (3)
Pd1—N1—N2—C8	−6.4 (4)	Pd1—N11—N12—C18	6.1 (4)
N1—N2—C3—C4	−0.9 (4)	N11—N12—C13—C14	−0.1 (5)
C8—N2—C3—C4	178.8 (4)	C18—N12—C13—C14	172.2 (4)
N1—N2—C3—C6	178.5 (4)	N11—N12—C13—C16	−178.4 (4)
C8—N2—C3—C6	−1.7 (7)	C18—N12—C13—C16	−6.1 (7)
N2—C3—C4—C5	0.6 (4)	N12—C13—C14—C15	−0.4 (5)
C6—C3—C4—C5	−178.8 (5)	C16—C13—C14—C15	177.7 (5)
N2—N1—C5—C4	−0.4 (4)	N12—N11—C15—C14	−0.8 (5)
Pd1—N1—C5—C4	−171.2 (3)	Pd1—N11—C15—C14	−179.3 (3)
N2—N1—C5—C7	179.1 (3)	N12—N11—C15—C17	177.5 (4)
Pd1—N1—C5—C7	8.3 (5)	Pd1—N11—C15—C17	−1.0 (7)
C3—C4—C5—N1	−0.1 (4)	C13—C14—C15—N11	0.8 (5)
C3—C4—C5—C7	−179.6 (4)	C13—C14—C15—C17	−177.4 (5)
C3—N2—C8—C9	−115.1 (4)	C13—N12—C18—C19	−113.4 (4)
N1—N2—C8—C9	64.6 (4)	N11—N12—C18—C19	58.3 (4)
N2—C8—C9—N10B	−75.9 (12)	C9—N10A—C19—C18	166.9 (4)
N2—C8—C9—N10A	−42.8 (5)	Pd1—N10A—C19—C18	30.0 (6)
N10B—C9—N10A—C19	−63.7 (12)	C9—N10A—C19—N10B	58.3 (11)
C8—C9—N10A—C19	−165.4 (4)	Pd1—N10A—C19—N10B	−78.6 (10)
N10B—C9—N10A—Pd1	74.3 (11)	N12—C18—C19—N10A	−77.7 (5)
C8—C9—N10A—Pd1	−27.4 (6)	N12—C18—C19—N10B	−46.7 (11)
N10A—C9—N10B—C19	68.0 (18)	C9—N10B—C19—N10A	−72.5 (18)
C8—C9—N10B—C19	160.4 (10)	Pd1—N10B—C19—N10A	64.0 (11)
N10A—C9—N10B—Pd1	−67.2 (12)	C9—N10B—C19—C18	−156.5 (11)
C8—C9—N10B—Pd1	25.2 (17)	Pd1—N10B—C19—C18	−20.0 (15)

D—H···A	D—H	H···A	D···A	D—H···A
N10A—H10A···N24ii	0.90	2.01	2.889 (9)	166
N10B—H10B···S1iii	0.90	2.71	3.52 (2)	151