The structure of chloro-bis(triphenylphosphine)silver(i) dimethylsulfoxide solvate, [AgCl(PPh 3

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1 ACTA UNIVERSITATIS PALACKIANAE OLOMUCENSIS FACULTAS RERUM NATURALIUM 1998 CHEMICA 37 The structure of chloro-bis(triphenylphosphine)silver(i) dimethylsulfoxide solvate, [AgCl(PPh 3 Zdeněk Trávníček, 1a Pavel Kopel 1 and Jaromír Marek 2 1 Department of Inorganic and Physical Chemistry, Palacký University, Křížkovského 10, Olomouc, Czech Republic; trav@risc.upol.cz 2 Department of Inorganic Chemistry, Masaryk University, Kotlářská 2, Brno, Czech Republic. Received May 31, 1998 Abstract The crystal and molecular structure of the title complex (C 38 H 36 AgClOP 2 S) was determined. The structure was solved by direct methods and refined anisotropically to R = for 3197 observed reflections. Crystals of [AgCl(PPh 3 crystallize in the monoclinic space group P2 1 /m with a = 8.531(2), b = (3), c = 9.531(2) Å, b= =114.56(3), Z = 2, T = 293 K, M r = , D c = g cm -3, V = (6) Å 3. X- ray analysis of the complex proves distorted trigonal geometry at the metal centre which can be changed to trigonal pyramidal by a weak interaction between silver(i) ion and oxygen atom of dimethylsulfoxide (2.609(3) Å).The molecule is symmetrical owing to the plane going through the Ag(1)-Cl(1) linkage with core distances and angles Ag(1)-P(1) = (7) and Ag(1)-Cl(1) = (11) Å, and P(1)-Ag(1)- P(1a) = (3), and P(1)-Ag(1)-Cl(1) = (2), respectively. Key Words: Silver(I) complex, triphenylphosphine, X-ray structure Introduction The silver(i) ion, as show X-ray studies, can exhibit variability of coordination polyhedron and coordination number varying from 2 to 4. The coordination number depends on bulkiness of the phosphine ligand and also on coordination ability of solvent. Also the counterion X (X = Cl, Br, I, NO 3, or ClO 4 ) plays an important role and can be either coordinated to metal centre or situated out of the coordination sphere. 1 Thus, in dependence on the steric and electronic profile of the phosphine ligand and the X ligand, monomeric [AgCl(PPh 3 ], 2 [Ag(NO 3 )(PPh 3 ], 3 [Ag(PPh 3 or [Ag(PPh 3 ) 4 ), 3 dimeric [Ag 2 X 2 (P-P ] {X = Cl, I, NO 3 ; 55

2 P-P=1,3-bis[(diphenylphosphino)methyl]benzene or X = I, Cl; 1,2-bis[(diphenylphosphino)-methyl]benzene} 1 or tetrameric cubane [Ag(PPh 2 Bu)X] 4 (X = Cl, Br, I) 4 complexes are formed. Many coordination compounds of silver(i) with triphenylphosphine have been prepared and structurally characterized to date. Here are examples of such complexes: [Ag(ac)(PPh 3 ] (ac = acetato), 5 [Ag(PPh 2 Cp ]BF 4 (Cp = cyclopentadienyl), 6 [AgCl(PPh 3 (py)] (py = pyridine), 7 [Ag(dtc)(PPh 3 ] (dtc= pyrrolidinedithocarbamato), 8 [Ag(pytH (PPh 3 ]NO 3 (pyth = pyridine-2-thione) 9 or [Ag(pymtH)(PPh 3 ]NO 3 (pymth = pyrimidine-2-thione). 9 Materials and Methods AgCl, triphenylphosphine (PPh 3 ) and all the solvents used were obtained from Lachema Co. and were of p.a. purity. The [AgCl(PPh 3 complex was prepared by the reaction of AgCl (1 mmol) with PPh 3 (2.2 mmol) in dimethylsulfoxide (20 cm 3 ). The mixture was boiled until AgCl completely dissolved. After a week standing at room temperature light-red crystals suitable for a single crystal X-ray analysis were obtained. Crystals were collected on a frit, washed with a small amount of dmso and dried in air. X-ray crystallography A crystal of dimensions of mm was used for data collection on a KUMA KM4 four-circle diffractometer with graphite monochromated MoK a radiation (l = Å). Unit cell dimensions were obtained by least-squares refinement of 50 reflections within the region of 16.6 < 2q < The intensities of 7335 reflections were measured with the w/2q scan method. The crystal stability during data collection was checked by monitoring of three standard reflections (1 0 0, 0 2 0, 0 0 1) after every 300 measurement; changes in their intensities were < 3.2 %. Absorption [DIFABS] 10 and extinction corrections were applied to data. The structure was solved by the heavy-atom method [SHELXS-96]. 11 All non-hydrogen atoms were refined anisotropically by the full-matrix least-squares procedure [SHELXL-96] 12 with weight: w = 1/[s(F 02 ) + (0.0493P P], where P = (F F c2 )/3. All H-atom positions were located from Fourier difference maps at an advanced stage of anisotropic refinement and all their parameters were refined, except of those bonded to carbons of dmso where U-parameters were fixed. Largest differences in the peak and hole on the final Fourier map were [1.81 Å from P(1)] and [1.27 Å from P(1)] e.å -3. Sulfur atoms of dmso are disodered with the value of occupancy factor 0.5. Crystal data and structure refinement parameters for [AgCl(PPh 3 are summarized in Tab. 1. Results and discussion The results of the single-crystal X-ray structure determination on the [AgCl(PPh 3 show that the coordination geometry about the silver atom is distorted trigonal-planar with an AgP 2 Cl chromophore. The coordination number can be increased to four by a weak bond interaction of Ag(I) with oxygen atom of 56

3 Table 1. Crystal data and structure refinement for [AgCl(PPh 3 Empirical formula C 38 H 36 Ag Cl O P 2 S Formula weight Temperature 293(2) K Wavelength Å Crystal system monoclinic Space group P2 1 /m Unit cell dimensions a = 8.531(2) Å a = 90 b = (3) Å b = (3) c = 9.531(2) Å g = 90 Volume (6) Å 3 Z 2 Density (calculated) Mg/m 3 Absorption coefficient mm -1 F(000) 764 Crystal size 0.80 x 0.40 x 0.30 mm 2q range for data collection 4.7 to 53.2 Index ranges -9 h 10, -29 k 29, -11 l 0 Reflections collected 7335 Independent reflections 3655 [R(int) = ] Refinement method Full-matrix least-squares on F 2 Data / restraints / parameters 3655 / 0 / 285 Goodness-of-fit on F Final R indices [I>2s(I)] R1 = 0.037, wr2 = R indices (all data) R1 = 0.050, wr2 = Largest diff. peak and hole and e.å -3 Table 2. Selected interatomic lengths [Å] and angles [ ] for [AgCl(PPh 3 Ag(1)-P(1a.4592(7) P(1a)-Ag(1)-P(1) (3) Ag(1)-P(1.4592(7) P(1a)-Ag(1)-Cl(1) (2) Ag(1)-Cl(1.5392(11) P(1)-Ag(1)-Cl(1) (2) Ag(1)-O(1.609(3) P(1a)-Ag(1)-O(1) 92.84(3) P(1)-C(31) 1.822(2) P(1)-Ag(1)-O(1) 92.84(32 P(1)-C(11) 1.824(2) Cl(1)-Ag(1)-O(1) (8) P(1)-C(21) 1.831(2) Symmetry transformations used to generate equivalent atoms: a x, -y +1/2, z 57

4 Table 3. Comparison of selected interatomic parameters (Å, ) in Ag(I)-complexes containig triphenylphosphine (PPh 3 ) [AgCl(PPh 3 a [Ag(PPh 3 ) [AgCl(PPh 3 ] [(PPh 3 Ag(m-thox)Ag(PPh 3 ] f Ag P (7.630(3) b 2.630(2) c 2.558(5) d 2.552(1) e 2.458(2) f 2.522(3.525(1.582(4.556(1.488(2) 2.551(3.545(2.576(3.520(1) Ag O 2.609(3.67(1.684(6) 2.510(6) 2.78(1.775(6) Ag Cl (11) 2.533(4.552(1) P Ag P (3) 112.4(1) (4) 115.7(1) (4) 122.2(1) 118.0(1) (5) 115.2(1) (4) 116.5(1) (5) 113.4(1) (1) a this work; b in Ref. [14]; c in Ref. [3]; d in Ref. [15]; e in Ref. [2]; f in Ref. [13] 58

5 Figure 1. Molecular structure of [AgCl(PPh 3 showing the atom numbering scheme. Hydrogen atoms are omitted for clarity. dimethylsulfoxide. Thus, the silver(i) ion may adopt a distorted trigonal-pyramidal geometry with an P 2 ClO donor set. The Ag(1)-O(1) separation in [AgCl(PPh 3 is equal to 2.609(3) Å. This value is somewhat higher than those found in [(PPh 3 Ag(mthox)Ag(PPh 3 ] (H 2 thox = 1,2-dithiooxalic acid) [2.510(6) Å]. 13 However, on the other hand, this bond dintance is shorter than in ionic considered compound of [Ag(PPh 3 ) [Ag O = 2.78(1) and 2.67(1) Å]. 14 A view of the molecule [AgCl(PPh 3 is shown in Figure 1. Important interatomic parameters are listed in Table 2. The AgP 2 Cl unit is nearly planar with the following deviations from the LSQ-plane formed by Ag(1), P(1), P(1a) and Cl(1) atoms: Ag(1) 0.179, P(1) 0.067, P(1a) and Cl(1) Å. The phosphorus carbon as well as carbon-carbon bond lengths appear to be normal with no significant variations. Comparison of selected bond distances and angles with those of the analogous Ag(I)-complexes is presented in Table 3. The Ag P bond lengths for all the complexes lie within the range 2.458(2) 2.630(3) Å and differ significantly from each other. Similarly, the P Ag P angle found in [AgCl(PPh 3 [137.13(3) ] is responsibly bigger than that in the 59

6 related complexes (see Table 3). Changes in these bond distances and angles are probably connected with the steric and electronic profile of anion which also has an influence on conformation of the coordination polyhedron. Supplementary Material Further details on the crystal structure analysis are deposited at the Cambridge Crystallographic Data Centre (CCDC) under the deposition number References 1. Caruso, F., Camalli, M., Rimml, H. and Venanzi, L. M.: Inorg. Chem. 34, 675 (1995). 2. Cassel, A.: Acta Crystallogr. B37, 229 (1981). 3. Barron, P. F., Dyason, J. C., Healy, P. C., Engelhardt, L. M., Skelton, B. W. and White, A. H.: Chem. Soc., Dalton Trans (1986). 4. Bowen, R. J., Camp, D., Effendy, Healy, P. C., Skelton, B. W. and White, A. H.: Aust. J. Chem. 47, 693 (1994). 5. Femi, B.: Z. Kristallogr. 52, 159 (1980). 6. Baiada, A., Jardine, F. H. and Willett, R. D.: Inorg. Chem. 29, 4805 (1990). 7. Effendy, Engelhardt, L.M., Healy, P. C., Skeaton, B. W. and White, A.: Aust. J. Chem. 44, 1585 (1991). 8. Othman, A. H., Fun, H.-K. and Sivakumaro, K.: Acta Crystallogr., C52, 843 (1996). 9. Aslanidis, P., Karagiannidis, P., Akrivos, P. D., Krebs, B. and Laege, M.: Inorg. Chim. Acta 254(2), 277 (1997). 10. Walker, N. and Stuart, D.: [DIFABS], Acta Crystallogr. A39, 158 (1983). 11. Sheldrick, G. M.: [SHELXS-96], Beta-test version, Acta Crystallogr. A46, 467 (1990). 12. Sheldrick, G. M.: [SHELXL-96], Beta-test version, Program for Crystal Structure Refinement. University of Göttingen, Germany (1996). 13. Golič, L., Bulc, N. and Dietzsch. W.: Polyhedron 2, 1201 (1983). 15. Bruce, M. I. And Duffy, D. N.: Aust. J. Chem. 39, 1691 (1986). 16. Engelhardt, L. M., Healy, P. C., Patrick, V. A. and White, A, H.: Aust. J. Chem. 40, 1873 (1987). 60