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On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part IV: Reactions with thiosemicarbazide monoaryl derivatives
Polyhedron 85 (2015) 161–164
Contents lists available at ScienceDirect
Polyhedron journal homepage: www.elsevier.com/locate/poly
On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part IV: Reactions with thiosemicarbazide monoaryl derivatives q Richard Ševcˇík, Jirˇí Prˇíhoda ⇑ Department of Chemistry, Faculty of Science, Masaryk University, Kotlárˇská 2, CZ-611 37 Brno, Czech Republic
a r t i c l e
i n f o
Article history: Received 3 July 2014 Accepted 5 August 2014 Available online 15 August 2014 Keywords: Five-membered heterocycle Thiosemicarbazide Chlorodithiophosphoric acid pyridiniumbetaine X-ray analysis NMR
a b s t r a c t In connection with our previous research, reactions of chlorodithiophosphoric acid pyridiniumbetaine, py.PS2Cl (I), with monoaryl thiosemicarbazide derivatives RN(H)C(S)N(H)NH2, (R = phenyl, 4-nitrophenyl) were studied with the aim to prepare new heterocyclic compounds. All reactions were carried out in acetonitrile in the presence of pyridine as an HCl acceptor. New compounds, pyridinium salts of 4-phenyl-3-sulfido-3,5-dithioxo-1,2,4,3k5-triazaphospholidine (II) and 4-(4-nitrophenyl)-3-sulfido-3, 5-dithioxo-1,2,4,3k5-triazaphospholidine (III) were prepared. 31P NMR, FT-IR, Raman spectroscopy, and X-ray diffraction analysis revealed their molecular structures consisting of pyridinium cation and fivemembered P–N–N–C–N heterocyclic anion bearing relevant aryl group. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Chlorodithiophosphoric acid pyridiniumbetaine, py.PS2Cl (I), can be used as a starting compound for synthesis of various linear or heterocyclic phosphorus atom containing compounds. Commonly, the reactions of I with polyfunctional nucleophiles, such as thiourea and its derivatives [1,2] and especially thiosemicarbazide derivatives, led to the formation of nitrogen-phosphorus heterocycles. The molecular structure of arising compounds is dependent on number of factors, especially on the presence or absence of an HCl acceptor in the reaction mixture, the type of an organic substituent bound to nucleophile, reaction time and temperature.
It was found that thiosemicarbazide compounds react with I to yield the heterocyclic compound Eq. (1) with five-membered P–N– N–C–N ring [3,4].
-
S S +
N
P -
S
R Cl +
S
H
H N
N C
NH2
pyridine - py.HCl
pyH
P
N
N
R
C
S
+
H
N H
S R = H (comp. A), ref. [3] Me (comp. B), ref. [4] Et (comp. C), ref. [4]
ð1Þ 0
q
Part I: On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with diphenylthiourea (V. Novomeˇstská, J. Marek, J. Prˇíhoda, Polyhedron 18 (1999) 2723–2727); On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part II. Reactions with thiosemicarbazide derivatives (M. Jancˇa, M. Necˇas, Z. Zˇák, J. Prˇíhoda, Polyhedron 20 (2001) 2823–2828); On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part III. Reactions with monoalkyl derivatives of thiosemicarbazide (R. Ševcˇík, J. Prˇíhoda, M. Necˇas, Polyhedron 24 (2005) 1855–1860). ⇑ Corresponding author. Address: Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic. Tel.: +420 549 49 6690; fax: +420 549 49 2443. E-mail address: [email protected] (J. Prˇíhoda). http://dx.doi.org/10.1016/j.poly.2014.08.022 0277-5387/Ó 2014 Elsevier Ltd. All rights reserved.
When non-symmetrically substituted N,N -disubstituted thiosemicarbazide derivatives are used for the reaction with I, two reaction products with different molecular structures can arise from the reaction mixture [5]. The structure determining factor is the presence or absence of triethylamine, which acts as an HCl acceptor in the course of reaction (Scheme 1). In the presence of triethylamine, heterocyclic compounds of the diazadiphosphetidine type (P–N–P–N heterocycle) are formed, while the reaction carried out without triethylamine led to the formation of the compound with unusual five membered P–N–N–C–S heterocyclic structure. Molecular structures of the latter compounds are of
R. Ševcˇík, J. Prˇíhoda / Polyhedron 85 (2015) 161–164
162
S
S R S +
N
P
R Cl + H N
-
S
Et3N
Me N C
N
C
H
-
Et 3NH + Me
P N
N
-
S
H
N
N
N
R
C
P
Me Et 3NH +
NH2
S
S
S
-
S
S S R
R = i-Pr, t-Bu
P
S +
N
C N Me
N
R
H
Scheme 1.
betaine type having one three-coordinated carbon atom bearing positive charge which is compensated by the negative charge of PS2 fragment. This article describes results obtained from the study of reactions of I with thiosemicarbazide monoaryl derivatives. The main aim of the study was to observe influence of aromatic substituents on the course of reactions and molecular structure of reaction products. In the case of reaction with 4-phenylthiosemicarbazide, the steric influence is predominantly expected, with regard to 4nitrophenyl group, the electronic influence should be considered as well. The intended reactions were expected to follow the course described in Eq. (1) but the different properties of arylthiosemicarbazides can lead the reactions to other, unexpected, compounds. 2. Experimental 2.1. Chemicals All chemicals were used as supplied (Aldrich, Lachema). Solvents were dried by standard methods and were distilled prior to their use [6]. Chlorodithiophosphoric acid pyridiniumbetaine (I) [7] and 4-phenylthiosemicarbazide were prepared according to the known procedures [8]. New derivative – 4-(4-nitrophenyl) thiosemicarbazide – was prepared in analogous way as phenylderivative. 2.2. Physical measurements The 31P NMR spectra were measured in acetonitrile using a Bruker AVANCE DRX 300 instrument and were referenced to 85% H3PO4. The IR spectra were recorded in nujol mulls on a Bruker IFS 28 spectrometer. The Raman spectra of solid samples were collected in Raman capillaries on a Bruker Equinox X55/S instrument. 2.3. X-ray measurements Diffraction data were collected on a KUMA KM-4 j-axis diffractometer equipped with CCD detector with graphite-monochromated Mo-Ka radiation (k = 0.71073 Å). The intensity data were corrected for Lorentz and polarization effects. All the structures were solved by direct methods and refined by full-matrix leastsquares methods using anisotropic thermal parameters for the non-hydrogen atoms. The software packages used were: Xcalibur CCD system [9] for the data collection/reduction, and SHELXTL [10] for the structure solution, refinement, and drawing preparation (thermal ellipsoids are drawn at the 50% probability level). 2.4. Synthetic procedures All reactions of I with arylthiosemicarbazide compounds were performed under dry nitrogen atmosphere in anhydrous solvents using conventional Schlenk techniques.
2.4.1. Reaction of py.PS2Cl with 4-phenylthiosemicarbazide – pyridinium salt of 4-phenyl-3-sulfido-3,5-dithioxo-1,2,4,3k5triazaphospholidine (II) Starting py.PS2Cl (0.877 g, 4.19 mmol) was dissolved in acetonitrile (38 ml) and pyridine (0.34 ml, 4.19 mmol) was added. Then 4-phenylthiosemicarbazide (0.700 g, 4.19 mmol) was put into the mixture which was then further stirred for 48 h at room temperature. The course of the reaction was observed by the 31P NMR spectroscopy. A small amount of insoluble by-products (as indicated by 31 P-NMR, DMF) was filtered off and the main reaction product was isolated from the reaction mixture by evaporating the solvent excess and keeping the concentrated solution in a cool place at – 25 °C. Solid product was then filtered off and dried in vacuum. White powder or colorless crystals, yield: 90% (with respect to I). 31P NMR (acetonitrile): d = 1120 ppm (singlet). IR: 3255 w, 3216 w, 3153 m, 3062 m, 3032 m, 1636 w, 1605 m, 1530 m, 1486 s, 1458 vs 1383 s, 1339 s, 1266 m, 1230 s, 1044 m, 921 w, 872 m, 826 m, 753 m, 738 m, 706 s, 671 s, 655 s, 617 s, 572 m, 525 s. RA: 3087 m, 3061 m, 1594 vw, 1285 vw, 1005 vs 623 m, 530 w, 433 s, 369 m.
2.4.2. Reaction of py.PS2Cl with 4-(4-nitrophenyl)thiosemicarbazide – pyridinium salt of 4-(4-nitrophenyl)-3-sulfido-3,5-dithioxo-1,2,4, 3k5-triazaphospholidine (III) Starting py.PS2Cl (0.244 g, 1.16 mmol) was dissolved in acetonitrile (13 ml) and pyridine (0.10 ml, 1.16 mmol) was added. Then 4-(4-nitrophenyl)thiosemicarbazide (0.247 g, 1.16 mmol) was put into the mixture which was then stirred for 48 h at room temperature. When thiosemicarbazide is dissolved, the reaction mixture has orange coloration. During the course of reaction solution, color changed to yellow and the yellow product started to precipitate. The course of the reaction was observed by the 31P NMR spectroscopy. The yellow solid was then filtered off and dried in vacuum. The next fraction of the product was obtained from concentrated solution upon standing at 25 °C. Yellow powder, yield: 93% (with respect to I). 31P NMR (acetonitrile): d = 112,1 ppm (singlet). IR: 3267 s, 3207 w, 3125 m, 3073 s, 3027 m, 1634 w, 1606 m, 1521 vs 1503 s, 1399 s, 1339 vs 1293 m, 1229 vs 1052 m, 902 m, 857 w, 811 vw, 747 s, 709 s, 675 vs 649 m, 605 w, 532 s. RA: 3265 vw, 3087 w, 1594 vs 1522 w, 1351 vs 1195 w, 1111 s, 1005 vs 856 s, 527 w, 403 s, 372 m, 302 m, 214 m.
3. Results and discussion Obtained results confirmed that I reacts with 4-arylthiosemicarbazides in analogous way as non-substituted thiosemicarbazide and its monoalkyl derivatives (see Eq. (1)) to yield analogous compounds with heterocyclic P–N–N–C–N anions bearing appropriate aryl group – pyridinium salt of 4-phenyl-3-sulfido3,5-dithioxo-1,2,4,3k5-triazaphospholidine (II) and pyridinium salt of 4-(p-nitrophenyl)-3-sulfido-3,5-dithioxo-1,2,4,3k5-triazaphospholidine (III). Compounds II and III can be considered as the only reaction products (excluding pyridinium chloride) although in case of phenylderivative a small amount of by-products is formed. They can be easily removed by filtration. The compounds II and III are very well soluble in acetonitrile (also well soluble in pyridine and DMF), contrary to analogous compound A, B, C. Due to higher solubility of the prepared compounds in acetonitrile, their isolation in a powdered or crystalline form can be rather complicated because solutions concentrated to small volumes form amorphous viscous phases in both cases. 31 P NMR spectra of both compounds are very simple and resonance peaks can be found in the same region – d = 112,0 ppm (II),
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163
Table 1 Basic crystallographic data and refinement parameters for compounds II and III.
Fig. 1. The ORTEP drawing of anionic part of compound II, showing the numbering scheme.
Empirical formula Formula weight Temperature (K) Crystal system Space group a (Å) b (Å) c (Å) a (°) b (°) c (°) Volume (Å3) Z Calculated density (Mg/m3) l (mm1) Crystal size (mm) h Range (°) Number of reflections Independent data Final R indices [I > 2r(I)] Final R indices [all data] Dqmax/Dqmin (e.A3)
II
III
C12 H13 N4 P S3 340.41 120(2) monoclinic P21/n 7.9272(14) 17.418(3) 10.991(3) 90 91.507(16) 90 1517.1(5) 4 1.490 0.588 0.50 0.50 0.40 3.34–25.00 12,739 2665 0.0355, 0.0851 0.0403, 0.0874 0.309 and 0.484
C12 H12 N5 O2 P S3 385.42 120(2) monoclinic P21/n 7.529(2) 19.905(4) 11.497(3) 90 101.78(2) 90 1686.6(7) 4 1.518 0.549 0.40 0.40 0.20 2.73–25.00 14,000 2967 0.0286, 0.0705 0.0468, 0.0742 0.331 and 0.280
Table 2 Selected bond lengths (Å) and angles (°) for compounds II and III.
Fig. 2. The ORTEP drawing of anionic part of compound III, showing the numbering scheme.
d = 112,1 ppm (III) – as for compounds B and C. No further splitting of the 31P signals due to P–H or P–N coupling were observed. FT-IR spectra of II and III have similar features as those of compounds B and C. There are many absorption bands belonging to aromatic rings vibrations (phenyl group and pyridine) that can be observed in typical regions; 3000–3180 cm1, 1400–1660 cm1 and 550–770 cm1. Bands above 3200 cm1 can be assigned to bonding vibrations of N–H bonds belonging to pyridinium cation (3214 cm1) and heterocyclic anion (3254 cm1). C@S bond absorption band can be found at 1050 cm1 for both of the compounds (1044 cm1 for II, 1052 cm1 for III). In the region of 550– 770 cm1 bands of PS2 group can be found (similar as for B and C) but they cannot be assigned surely due to their overlap with bands of aromatic rings. In case of III very strong bands at 1522, 1341 and 527 cm1 belonging to NO2 group vibrations dominate the whole spectrum. Molecular structures of compounds II and III were definitely confirmed by X-ray diffraction analysis of suitable single crystals (Figs. 1 and 2) that were grown from the concentrated reaction mixtures over a few days at room temperature or lower if needed. Lattice parameters and other crystallographic data for compounds II and III are given in Table 1, selected bond lengths and angles in
II
III
P(1)–S(1) P(1)–S(2) P(1)–N(1) P(1)–N(3) N(1)–N(2) N(2)–C(1) N(3)–C(1) N(3)–C(2) S(3)–C(1)
1.9502(9) 1.9480(8) 1.727(2) 1.754(2) 1.429(3) 1.353(3) 1.353(3) 1.439(3) 1.676(2)
1.9668(8) 1.9562(9) 1.710(2) 1.759(2) 1.433(3) 1.333(3) 1.372(3) 1.432(3) 1.689(2)
S(2)–P(1)–S(1) N(1)–P(1)–N(3) C(1)–N(3)–C(2) C(1)–N(3)–P(1) N(2)–N(1)–P(1) C(1)–N(2)–N(1) N(3)–C(1)–N(2) N(3)–C(1)–S(3) N(2)–C(1)–S(3)
119.89(4) 89.39(9) 123.9(2) 110.9(1) 106.8(2) 115.4(2) 110.8(2) 126.2(2) 123.0(2)
118.52(3) 89.85(8) 124.6(2) 111.6(1) 107.5(1) 116.6(2) 110.2(2) 125.6(2) 124.2(2)
Table 2, and hydrogen bonding parameters in Table 3. The molecular and crystal structures are drawn in Figs. 1–3. The crystals of both II and III are monoclinic with P21/n space group. Pyridinium chloride (a by-product) was not found to be present in crystal lattices of compound II and III as it was in case of compounds A, B and C, nevertheless, the molecular structures of II and III are very similar to them and all of the structures can be compared. It can be clearly seen that molecular structures of all above mentioned compounds consist of pyridinium cation and heterocyclic P–N–N–C–N anion bearing appropriate organic substituent in position 4 or hydrogen atom in case of A. Five-membered P–N–N–C–N rings of II and III exhibit similar degree of deviation from P(1)–N(1)–N(2)–C(1)–N(3) plane (r.m.s. deviations 0.1217 Å for II, 0.0971 Å for III) as those of B (0.1126 Å) and C (0.0795 Å). This means that P–N–N–C–N rings are more distorted when aliphatic or aromatic group is bound (r.m.s. deviation for unsubstituted ring of A is 0.0400 Å). The bonding geometry on nitrogen atoms in the cycles varies from expected trigonal pyramidal in case of N(1) to unexpected trigonal planar geometry for nitrogen N(2) and especially for nitrogen N(3) which bears aryl group (sum of
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164
Table 3 Hydrogen bonding parameters (Å, °) for compounds II and III. D–HA
D–H
HA
DA
\D–HA
II N(2)–H(2A)...S(3)a N(10)–H(10A)...S(1) N(10)–H(10A)...S(2)
0.81(3) 0.88 0.88
2.50(3) 2.71 2.93
3.305(2) 3.417(2) 3.456(2)
172(3) 138.3 120.3
III N(1)–H(1A)...O(2)a N(2)–H(2A)...S(3)b N(10)c–H(10A)c...S(1)
0.81(2) 0.84(2) 0.88
2.21(2) 2.46(2) 2.57
2.865(2) 3.3007(19) 3.401(2)
138.3(19) 178(2) 158.2
Symmetry transformations used to generate equivalent atoms (II): ax+1, y, z. Symmetry transformations used to generate equivalent atoms (III): ax1/2, y1/ 2, z+1/2; bx, y, z+1; cx1/2, y+1/2, z1/2.
lengths differ (1.9668(8) Å for P(1)–S(1) and 1.9562(9) Å for P(1)– S(2)), probably due to different intermolecular interactions. As chloride anions (from by-product – pyridinium chloride) were not found in the crystal lattices of II and III to participate in intermolecular bondings, hydrogen interactions in crystal structures of II and III are different in comparison with structures of B and C. But similarities can be seen in all cases. Also molecules of II and III tend to associate into dimeric species but in case of II and III two heterocyclic anions are linked through symmetric C(1)@S(3) H–N(2) bridges. Significant interactions between heterocyclic anion and pyridinium cation through P(1)–S H–Npyr bridges can be seen, although in case of III only one sulfur atom of the PS2 group is involved. In crystal structure of III (Fig. 3) additional intermolecular interactions due to NO2 group were observed. Through the N(4)–O(2) H–N(1) intermolecular interactions heterocyclic anions are linked into chains. Acknowledgements This work was supported by the FRVŠ Grant No. 576/2004, Ministry of Education, Czech Republic. We are also very grateful to Marek Necˇas for valuable discussion and contribution to X-ray structure analysis. Appendix A. Supplementary data
Fig. 3. The ORTEP drawing of crystal structure of III (symmetry transformations used to generate equivalent atoms: ax1/2, y1/2, z+1/2; bx, y, z+1; cx1/ 2, y+1/2, z1/2).
CCDC 1009744 and 1009745 contain the supplementary crystallographic data for compounds II and III. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/ retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223336-033; or e-mail: [email protected]. References
bonding angles on N(3) is 357.8 ° for II and 357.1 ° for III). Although this distortion can be partly assigned to intermolecular interactions in case of N–H bonds, in case of N(3) there are no such interactions. In consequence, some delocalization of the free electron pair of nitrogen atoms N(3) and N(2) have to be considered, in case of N(3) the steric influence of the organic group may be contributing. But it is in good agreement with observations of molecular structures of compounds B and C. Exocyclic P–S bonds in compound II have almost the same length (1.9502(9) Å for P(1)–S(1) and 1.9480(8) Å for P(1)–S(2)) and both of them are involved in intermolecular interactions. In case of III PAS bonds
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
V. Novomeˇstská, J. Marek, J. Prˇíhoda, Polyhedron 18 (1999) 2723. R. Skácel, Diploma thesis, Masaryk university Brno, 2001. M. Jancˇa, Dissertation, Masaryk University Brno, 2002. R. Ševcˇík, J. Prˇíhoda, M. Necˇas, Polyhedron 24 (2005) 1855. M. Jancˇa, M. Necˇas, Z. Zˇák, J. Prˇíhoda, Polyhedron 20 (2001) 2823. D.D. Perrin, W.L.F. Armarego, Purification of Laboratory Chemicals, Pergamon Press, Oxford, 1988. M. Meisel, H. Grunze, Z. Anorg, Allg. Chem. 360 (1968) 277. K.A. Jensen, U. Anthoni, B. Kägi, Ch. Larsen, C.T. Pedersen, Acta Chem. Scand. 22 (1968) 1. Oxford Diffraction Ltd., XCALIBUR CCD System, CrysAlis Software System, Version 1.168, Oxford, England, 2001. G.M. Sheldrick, Acta Crystallogr. Sect. A 64 (2008) 112.
Contents lists available at ScienceDirect
Polyhedron journal homepage: www.elsevier.com/locate/poly
On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part IV: Reactions with thiosemicarbazide monoaryl derivatives q Richard Ševcˇík, Jirˇí Prˇíhoda ⇑ Department of Chemistry, Faculty of Science, Masaryk University, Kotlárˇská 2, CZ-611 37 Brno, Czech Republic
a r t i c l e
i n f o
Article history: Received 3 July 2014 Accepted 5 August 2014 Available online 15 August 2014 Keywords: Five-membered heterocycle Thiosemicarbazide Chlorodithiophosphoric acid pyridiniumbetaine X-ray analysis NMR
a b s t r a c t In connection with our previous research, reactions of chlorodithiophosphoric acid pyridiniumbetaine, py.PS2Cl (I), with monoaryl thiosemicarbazide derivatives RN(H)C(S)N(H)NH2, (R = phenyl, 4-nitrophenyl) were studied with the aim to prepare new heterocyclic compounds. All reactions were carried out in acetonitrile in the presence of pyridine as an HCl acceptor. New compounds, pyridinium salts of 4-phenyl-3-sulfido-3,5-dithioxo-1,2,4,3k5-triazaphospholidine (II) and 4-(4-nitrophenyl)-3-sulfido-3, 5-dithioxo-1,2,4,3k5-triazaphospholidine (III) were prepared. 31P NMR, FT-IR, Raman spectroscopy, and X-ray diffraction analysis revealed their molecular structures consisting of pyridinium cation and fivemembered P–N–N–C–N heterocyclic anion bearing relevant aryl group. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Chlorodithiophosphoric acid pyridiniumbetaine, py.PS2Cl (I), can be used as a starting compound for synthesis of various linear or heterocyclic phosphorus atom containing compounds. Commonly, the reactions of I with polyfunctional nucleophiles, such as thiourea and its derivatives [1,2] and especially thiosemicarbazide derivatives, led to the formation of nitrogen-phosphorus heterocycles. The molecular structure of arising compounds is dependent on number of factors, especially on the presence or absence of an HCl acceptor in the reaction mixture, the type of an organic substituent bound to nucleophile, reaction time and temperature.
It was found that thiosemicarbazide compounds react with I to yield the heterocyclic compound Eq. (1) with five-membered P–N– N–C–N ring [3,4].
-
S S +
N
P -
S
R Cl +
S
H
H N
N C
NH2
pyridine - py.HCl
pyH
P
N
N
R
C
S
+
H
N H
S R = H (comp. A), ref. [3] Me (comp. B), ref. [4] Et (comp. C), ref. [4]
ð1Þ 0
q
Part I: On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with diphenylthiourea (V. Novomeˇstská, J. Marek, J. Prˇíhoda, Polyhedron 18 (1999) 2723–2727); On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part II. Reactions with thiosemicarbazide derivatives (M. Jancˇa, M. Necˇas, Z. Zˇák, J. Prˇíhoda, Polyhedron 20 (2001) 2823–2828); On the reactions of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles. Part III. Reactions with monoalkyl derivatives of thiosemicarbazide (R. Ševcˇík, J. Prˇíhoda, M. Necˇas, Polyhedron 24 (2005) 1855–1860). ⇑ Corresponding author. Address: Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic. Tel.: +420 549 49 6690; fax: +420 549 49 2443. E-mail address: [email protected] (J. Prˇíhoda). http://dx.doi.org/10.1016/j.poly.2014.08.022 0277-5387/Ó 2014 Elsevier Ltd. All rights reserved.
When non-symmetrically substituted N,N -disubstituted thiosemicarbazide derivatives are used for the reaction with I, two reaction products with different molecular structures can arise from the reaction mixture [5]. The structure determining factor is the presence or absence of triethylamine, which acts as an HCl acceptor in the course of reaction (Scheme 1). In the presence of triethylamine, heterocyclic compounds of the diazadiphosphetidine type (P–N–P–N heterocycle) are formed, while the reaction carried out without triethylamine led to the formation of the compound with unusual five membered P–N–N–C–S heterocyclic structure. Molecular structures of the latter compounds are of
R. Ševcˇík, J. Prˇíhoda / Polyhedron 85 (2015) 161–164
162
S
S R S +
N
P
R Cl + H N
-
S
Et3N
Me N C
N
C
H
-
Et 3NH + Me
P N
N
-
S
H
N
N
N
R
C
P
Me Et 3NH +
NH2
S
S
S
-
S
S S R
R = i-Pr, t-Bu
P
S +
N
C N Me
N
R
H
Scheme 1.
betaine type having one three-coordinated carbon atom bearing positive charge which is compensated by the negative charge of PS2 fragment. This article describes results obtained from the study of reactions of I with thiosemicarbazide monoaryl derivatives. The main aim of the study was to observe influence of aromatic substituents on the course of reactions and molecular structure of reaction products. In the case of reaction with 4-phenylthiosemicarbazide, the steric influence is predominantly expected, with regard to 4nitrophenyl group, the electronic influence should be considered as well. The intended reactions were expected to follow the course described in Eq. (1) but the different properties of arylthiosemicarbazides can lead the reactions to other, unexpected, compounds. 2. Experimental 2.1. Chemicals All chemicals were used as supplied (Aldrich, Lachema). Solvents were dried by standard methods and were distilled prior to their use [6]. Chlorodithiophosphoric acid pyridiniumbetaine (I) [7] and 4-phenylthiosemicarbazide were prepared according to the known procedures [8]. New derivative – 4-(4-nitrophenyl) thiosemicarbazide – was prepared in analogous way as phenylderivative. 2.2. Physical measurements The 31P NMR spectra were measured in acetonitrile using a Bruker AVANCE DRX 300 instrument and were referenced to 85% H3PO4. The IR spectra were recorded in nujol mulls on a Bruker IFS 28 spectrometer. The Raman spectra of solid samples were collected in Raman capillaries on a Bruker Equinox X55/S instrument. 2.3. X-ray measurements Diffraction data were collected on a KUMA KM-4 j-axis diffractometer equipped with CCD detector with graphite-monochromated Mo-Ka radiation (k = 0.71073 Å). The intensity data were corrected for Lorentz and polarization effects. All the structures were solved by direct methods and refined by full-matrix leastsquares methods using anisotropic thermal parameters for the non-hydrogen atoms. The software packages used were: Xcalibur CCD system [9] for the data collection/reduction, and SHELXTL [10] for the structure solution, refinement, and drawing preparation (thermal ellipsoids are drawn at the 50% probability level). 2.4. Synthetic procedures All reactions of I with arylthiosemicarbazide compounds were performed under dry nitrogen atmosphere in anhydrous solvents using conventional Schlenk techniques.
2.4.1. Reaction of py.PS2Cl with 4-phenylthiosemicarbazide – pyridinium salt of 4-phenyl-3-sulfido-3,5-dithioxo-1,2,4,3k5triazaphospholidine (II) Starting py.PS2Cl (0.877 g, 4.19 mmol) was dissolved in acetonitrile (38 ml) and pyridine (0.34 ml, 4.19 mmol) was added. Then 4-phenylthiosemicarbazide (0.700 g, 4.19 mmol) was put into the mixture which was then further stirred for 48 h at room temperature. The course of the reaction was observed by the 31P NMR spectroscopy. A small amount of insoluble by-products (as indicated by 31 P-NMR, DMF) was filtered off and the main reaction product was isolated from the reaction mixture by evaporating the solvent excess and keeping the concentrated solution in a cool place at – 25 °C. Solid product was then filtered off and dried in vacuum. White powder or colorless crystals, yield: 90% (with respect to I). 31P NMR (acetonitrile): d = 1120 ppm (singlet). IR: 3255 w, 3216 w, 3153 m, 3062 m, 3032 m, 1636 w, 1605 m, 1530 m, 1486 s, 1458 vs 1383 s, 1339 s, 1266 m, 1230 s, 1044 m, 921 w, 872 m, 826 m, 753 m, 738 m, 706 s, 671 s, 655 s, 617 s, 572 m, 525 s. RA: 3087 m, 3061 m, 1594 vw, 1285 vw, 1005 vs 623 m, 530 w, 433 s, 369 m.
2.4.2. Reaction of py.PS2Cl with 4-(4-nitrophenyl)thiosemicarbazide – pyridinium salt of 4-(4-nitrophenyl)-3-sulfido-3,5-dithioxo-1,2,4, 3k5-triazaphospholidine (III) Starting py.PS2Cl (0.244 g, 1.16 mmol) was dissolved in acetonitrile (13 ml) and pyridine (0.10 ml, 1.16 mmol) was added. Then 4-(4-nitrophenyl)thiosemicarbazide (0.247 g, 1.16 mmol) was put into the mixture which was then stirred for 48 h at room temperature. When thiosemicarbazide is dissolved, the reaction mixture has orange coloration. During the course of reaction solution, color changed to yellow and the yellow product started to precipitate. The course of the reaction was observed by the 31P NMR spectroscopy. The yellow solid was then filtered off and dried in vacuum. The next fraction of the product was obtained from concentrated solution upon standing at 25 °C. Yellow powder, yield: 93% (with respect to I). 31P NMR (acetonitrile): d = 112,1 ppm (singlet). IR: 3267 s, 3207 w, 3125 m, 3073 s, 3027 m, 1634 w, 1606 m, 1521 vs 1503 s, 1399 s, 1339 vs 1293 m, 1229 vs 1052 m, 902 m, 857 w, 811 vw, 747 s, 709 s, 675 vs 649 m, 605 w, 532 s. RA: 3265 vw, 3087 w, 1594 vs 1522 w, 1351 vs 1195 w, 1111 s, 1005 vs 856 s, 527 w, 403 s, 372 m, 302 m, 214 m.
3. Results and discussion Obtained results confirmed that I reacts with 4-arylthiosemicarbazides in analogous way as non-substituted thiosemicarbazide and its monoalkyl derivatives (see Eq. (1)) to yield analogous compounds with heterocyclic P–N–N–C–N anions bearing appropriate aryl group – pyridinium salt of 4-phenyl-3-sulfido3,5-dithioxo-1,2,4,3k5-triazaphospholidine (II) and pyridinium salt of 4-(p-nitrophenyl)-3-sulfido-3,5-dithioxo-1,2,4,3k5-triazaphospholidine (III). Compounds II and III can be considered as the only reaction products (excluding pyridinium chloride) although in case of phenylderivative a small amount of by-products is formed. They can be easily removed by filtration. The compounds II and III are very well soluble in acetonitrile (also well soluble in pyridine and DMF), contrary to analogous compound A, B, C. Due to higher solubility of the prepared compounds in acetonitrile, their isolation in a powdered or crystalline form can be rather complicated because solutions concentrated to small volumes form amorphous viscous phases in both cases. 31 P NMR spectra of both compounds are very simple and resonance peaks can be found in the same region – d = 112,0 ppm (II),
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Table 1 Basic crystallographic data and refinement parameters for compounds II and III.
Fig. 1. The ORTEP drawing of anionic part of compound II, showing the numbering scheme.
Empirical formula Formula weight Temperature (K) Crystal system Space group a (Å) b (Å) c (Å) a (°) b (°) c (°) Volume (Å3) Z Calculated density (Mg/m3) l (mm1) Crystal size (mm) h Range (°) Number of reflections Independent data Final R indices [I > 2r(I)] Final R indices [all data] Dqmax/Dqmin (e.A3)
II
III
C12 H13 N4 P S3 340.41 120(2) monoclinic P21/n 7.9272(14) 17.418(3) 10.991(3) 90 91.507(16) 90 1517.1(5) 4 1.490 0.588 0.50 0.50 0.40 3.34–25.00 12,739 2665 0.0355, 0.0851 0.0403, 0.0874 0.309 and 0.484
C12 H12 N5 O2 P S3 385.42 120(2) monoclinic P21/n 7.529(2) 19.905(4) 11.497(3) 90 101.78(2) 90 1686.6(7) 4 1.518 0.549 0.40 0.40 0.20 2.73–25.00 14,000 2967 0.0286, 0.0705 0.0468, 0.0742 0.331 and 0.280
Table 2 Selected bond lengths (Å) and angles (°) for compounds II and III.
Fig. 2. The ORTEP drawing of anionic part of compound III, showing the numbering scheme.
d = 112,1 ppm (III) – as for compounds B and C. No further splitting of the 31P signals due to P–H or P–N coupling were observed. FT-IR spectra of II and III have similar features as those of compounds B and C. There are many absorption bands belonging to aromatic rings vibrations (phenyl group and pyridine) that can be observed in typical regions; 3000–3180 cm1, 1400–1660 cm1 and 550–770 cm1. Bands above 3200 cm1 can be assigned to bonding vibrations of N–H bonds belonging to pyridinium cation (3214 cm1) and heterocyclic anion (3254 cm1). C@S bond absorption band can be found at 1050 cm1 for both of the compounds (1044 cm1 for II, 1052 cm1 for III). In the region of 550– 770 cm1 bands of PS2 group can be found (similar as for B and C) but they cannot be assigned surely due to their overlap with bands of aromatic rings. In case of III very strong bands at 1522, 1341 and 527 cm1 belonging to NO2 group vibrations dominate the whole spectrum. Molecular structures of compounds II and III were definitely confirmed by X-ray diffraction analysis of suitable single crystals (Figs. 1 and 2) that were grown from the concentrated reaction mixtures over a few days at room temperature or lower if needed. Lattice parameters and other crystallographic data for compounds II and III are given in Table 1, selected bond lengths and angles in
II
III
P(1)–S(1) P(1)–S(2) P(1)–N(1) P(1)–N(3) N(1)–N(2) N(2)–C(1) N(3)–C(1) N(3)–C(2) S(3)–C(1)
1.9502(9) 1.9480(8) 1.727(2) 1.754(2) 1.429(3) 1.353(3) 1.353(3) 1.439(3) 1.676(2)
1.9668(8) 1.9562(9) 1.710(2) 1.759(2) 1.433(3) 1.333(3) 1.372(3) 1.432(3) 1.689(2)
S(2)–P(1)–S(1) N(1)–P(1)–N(3) C(1)–N(3)–C(2) C(1)–N(3)–P(1) N(2)–N(1)–P(1) C(1)–N(2)–N(1) N(3)–C(1)–N(2) N(3)–C(1)–S(3) N(2)–C(1)–S(3)
119.89(4) 89.39(9) 123.9(2) 110.9(1) 106.8(2) 115.4(2) 110.8(2) 126.2(2) 123.0(2)
118.52(3) 89.85(8) 124.6(2) 111.6(1) 107.5(1) 116.6(2) 110.2(2) 125.6(2) 124.2(2)
Table 2, and hydrogen bonding parameters in Table 3. The molecular and crystal structures are drawn in Figs. 1–3. The crystals of both II and III are monoclinic with P21/n space group. Pyridinium chloride (a by-product) was not found to be present in crystal lattices of compound II and III as it was in case of compounds A, B and C, nevertheless, the molecular structures of II and III are very similar to them and all of the structures can be compared. It can be clearly seen that molecular structures of all above mentioned compounds consist of pyridinium cation and heterocyclic P–N–N–C–N anion bearing appropriate organic substituent in position 4 or hydrogen atom in case of A. Five-membered P–N–N–C–N rings of II and III exhibit similar degree of deviation from P(1)–N(1)–N(2)–C(1)–N(3) plane (r.m.s. deviations 0.1217 Å for II, 0.0971 Å for III) as those of B (0.1126 Å) and C (0.0795 Å). This means that P–N–N–C–N rings are more distorted when aliphatic or aromatic group is bound (r.m.s. deviation for unsubstituted ring of A is 0.0400 Å). The bonding geometry on nitrogen atoms in the cycles varies from expected trigonal pyramidal in case of N(1) to unexpected trigonal planar geometry for nitrogen N(2) and especially for nitrogen N(3) which bears aryl group (sum of
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Table 3 Hydrogen bonding parameters (Å, °) for compounds II and III. D–HA
D–H
HA
DA
\D–HA
II N(2)–H(2A)...S(3)a N(10)–H(10A)...S(1) N(10)–H(10A)...S(2)
0.81(3) 0.88 0.88
2.50(3) 2.71 2.93
3.305(2) 3.417(2) 3.456(2)
172(3) 138.3 120.3
III N(1)–H(1A)...O(2)a N(2)–H(2A)...S(3)b N(10)c–H(10A)c...S(1)
0.81(2) 0.84(2) 0.88
2.21(2) 2.46(2) 2.57
2.865(2) 3.3007(19) 3.401(2)
138.3(19) 178(2) 158.2
Symmetry transformations used to generate equivalent atoms (II): ax+1, y, z. Symmetry transformations used to generate equivalent atoms (III): ax1/2, y1/ 2, z+1/2; bx, y, z+1; cx1/2, y+1/2, z1/2.
lengths differ (1.9668(8) Å for P(1)–S(1) and 1.9562(9) Å for P(1)– S(2)), probably due to different intermolecular interactions. As chloride anions (from by-product – pyridinium chloride) were not found in the crystal lattices of II and III to participate in intermolecular bondings, hydrogen interactions in crystal structures of II and III are different in comparison with structures of B and C. But similarities can be seen in all cases. Also molecules of II and III tend to associate into dimeric species but in case of II and III two heterocyclic anions are linked through symmetric C(1)@S(3) H–N(2) bridges. Significant interactions between heterocyclic anion and pyridinium cation through P(1)–S H–Npyr bridges can be seen, although in case of III only one sulfur atom of the PS2 group is involved. In crystal structure of III (Fig. 3) additional intermolecular interactions due to NO2 group were observed. Through the N(4)–O(2) H–N(1) intermolecular interactions heterocyclic anions are linked into chains. Acknowledgements This work was supported by the FRVŠ Grant No. 576/2004, Ministry of Education, Czech Republic. We are also very grateful to Marek Necˇas for valuable discussion and contribution to X-ray structure analysis. Appendix A. Supplementary data
Fig. 3. The ORTEP drawing of crystal structure of III (symmetry transformations used to generate equivalent atoms: ax1/2, y1/2, z+1/2; bx, y, z+1; cx1/ 2, y+1/2, z1/2).
CCDC 1009744 and 1009745 contain the supplementary crystallographic data for compounds II and III. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/ retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223336-033; or e-mail: [email protected]. References
bonding angles on N(3) is 357.8 ° for II and 357.1 ° for III). Although this distortion can be partly assigned to intermolecular interactions in case of N–H bonds, in case of N(3) there are no such interactions. In consequence, some delocalization of the free electron pair of nitrogen atoms N(3) and N(2) have to be considered, in case of N(3) the steric influence of the organic group may be contributing. But it is in good agreement with observations of molecular structures of compounds B and C. Exocyclic P–S bonds in compound II have almost the same length (1.9502(9) Å for P(1)–S(1) and 1.9480(8) Å for P(1)–S(2)) and both of them are involved in intermolecular interactions. In case of III PAS bonds
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