organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoIUCrDATA
ISSN: 2414-3146

1-{2-Anilino-4-methyl-5-[5-methyl-1-(4-methyl­phen­yl)-1H-1,2,3-triazole-4-carbon­yl]thio­phen-3-yl}ethanone

CROSSMARK_Color_square_no_text.svg

aCornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, PO Box 10219, Riyadh 11433, Saudi Arabia, bDepartment of Chemistry, College of Science and Humanities, Shaqra University, Duwadimi, Saudi Arabia, cApplied Organic Chemistry Department, National Research Centre, Dokki, Giza, Egypt, dChemistry Department, Faculty of Science, Jazan University, Jazan 2079, Saudi Arabia, eChemical Industries Division, National Research Centre, Dokki 12622, Giza, Egypt, fChemistry Department, Faculty of Science, Damietta University, Egypt, and gSchool of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
*Correspondence e-mail: gelhiti@ksu.edu.sa

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 2 March 2018; accepted 8 March 2018; online 15 March 2018)

In the title compound, C24H22N4O2S, the dihedral angle between the triazole and thio­phene rings is 4.83 (14)°. The dihedral angles between the triazole and tolyl rings and between the thio­phene and phenyl rings are 48.42 (16) and 9.23 (13)°, respectively. An intra­molecular N—H⋯O hydrogen bond closes an S(6) loop. In the crystal, mol­ecules are stacked parallel to the a-axis direction with weak ππ inter­actions between adjacent thio­phenyl and triazolyl groups within the stack [centroid–centroid separation = 3.9811 (16) Å].

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Heterocycles containing 1,2,3-triazole and thio­phene moieties have a wide range of applications (Dheer et al., 2017[Dheer, D., Singh, V. & Shankar, R. (2017). Bioorg. Chem. 71, 30-54.]; Jiang & Kuang, 2013[Jiang, Y. & Kuang, C. (2013). Mini Rev. Med. Chem. 13, 713-719.]; Li et al., 2016[Li, L., Zhao, C. & Wang, H. (2016). Chem. Rec. 16, 797-809.]; Mancuso & Gabriele, 2014[Mancuso, R. & Gabriele, B. (2014). Molecules, 19, 15687-15719.]; Shafran et al., 2008[Shafran, E. A., Bakulev, V. A., Rozin, Yu. A. & Shafran, Yu. M. (2008). Chem. Heterocycl. Compd, 44, 1040-1069.]; Yamada et al., 2018[Yamada, M., Takahashi, T., Hasegawa, M., Matsumura, M., Ono, K., Fujimoto, R., Kitamura, Y., Murata, Y., Kakusawa, N., Tanaka, M., Obata, T., Fujiwara, Y. & Yasuike, S. (2018). Bioorg. Med. Chem. Lett. 28, 152-154.]). As part of our studies in this area, we now describe the crystal structure of the title compound.

The asymmetric unit consists of one mol­ecule of C24H22N4O2S (Fig. 1[link]). The dihedral angle between the triazole and thio­phene rings is 4.83 (14)°. The dihedral angles between the triazole and tolyl rings and between the thio­phene and phenyl rings are 48.42 (16) and 9.23 (13)°, respectively. An intra­molecular N4—H4A⋯O2 hydrogen bond closes an S(6) loop (Table 1[link]). In the crystal, the mol­ecules are stacked parallel to the a-axis direction with weak ππ inter­actions [centroid–centroid separation = 3.9811 (16) Å] between adjacent thio­phenyl and triazolyl groups within the stack (Figs. 2[link] and 3[link]).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N4—H4A⋯O2 0.86 1.91 2.605 (3) 137
[Figure 1]
Figure 1
The mol­ecular structure of the title compound, showing 50% probability displacement ellipsoids and the intra­molecular N—H⋯O hydrogen bond (dashed lines).
[Figure 2]
Figure 2
Crystal packing viewed down the a axis.
[Figure 3]
Figure 3
A segment of the crystal structure showing ππ contacts within a stack.

Synthesis and crystallization

The title compound was obtained using a literature procedure (Mohamed et al., 2017[Mohamed, H. A., Abdel-Wahab, B. F. & El-Hiti, G. A. (2017). Heterocycles, 94, 716-726.]). Yellow plates were recrystallized from di­methyl­formamide soluton in 74% yield; m.p. 222–224°C.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C24H22N4O2S
Mr 430.51
Crystal system, space group Monoclinic, P21/c
Temperature (K) 296
a, b, c (Å) 6.2938 (5), 10.9254 (9), 31.229 (4)
β (°) 90.221 (8)
V3) 2147.4 (4)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.18
Crystal size (mm) 0.60 × 0.15 × 0.06
 
Data collection
Diffractometer Rigaku Oxford Diffraction SuperNova, Dual, Cu at zero, Atlas
Absorption correction Gaussian (CrysAlis PRO; Rigaku OD, 2015[Rigaku OD (2015). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.])
Tmin, Tmax 0.993, 0.998
No. of measured, independent and observed [I > 2σ(I)] reflections 18565, 5355, 2925
Rint 0.058
(sin θ/λ)max−1) 0.703
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.061, 0.150, 1.03
No. of reflections 5355
No. of parameters 284
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.17, −0.23
Computer programs: CrysAlis PRO (Rigaku OD, 2015[Rigaku OD (2015). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2018 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), ORTEP-3 for Windows and WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and CHEMDRAW Ultra (Cambridge Soft, 2001[Cambridge Soft (2001). CHEMDRAW Ultra. Cambridge Soft Corporation, Cambridge, Massachusetts, USA.]).

Structural data


Computing details top

Data collection: CrysAlis PRO (Rigaku OD, 2015); cell refinement: CrysAlis PRO (Rigaku OD, 2015); data reduction: CrysAlis PRO (Rigaku OD, 2015); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and CHEMDRAW Ultra (Cambridge Soft, 2001).

1-{2-Anilino-4-methyl-5-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazole-4-carbonyl]thiophen-3-yl}ethanone top
Crystal data top
C24H22N4O2SF(000) = 904
Mr = 430.51Dx = 1.332 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 6.2938 (5) ÅCell parameters from 3306 reflections
b = 10.9254 (9) Åθ = 3.7–25.6°
c = 31.229 (4) ŵ = 0.18 mm1
β = 90.221 (8)°T = 296 K
V = 2147.4 (4) Å3Plate, yellow
Z = 40.60 × 0.15 × 0.06 mm
Data collection top
Rigaku Oxford Diffraction SuperNova, Dual, Cu at zero, Atlas
diffractometer
2925 reflections with I > 2σ(I)
ω scansRint = 0.058
Absorption correction: gaussian
(CrysAlis PRO; Rigaku OD, 2015)
θmax = 30.0°, θmin = 3.5°
Tmin = 0.993, Tmax = 0.998h = 87
18565 measured reflectionsk = 1415
5355 independent reflectionsl = 4236
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.061H-atom parameters constrained
wR(F2) = 0.150 w = 1/[σ2(Fo2) + (0.044P)2 + 0.7067P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max < 0.001
5355 reflectionsΔρmax = 0.17 e Å3
284 parametersΔρmin = 0.23 e Å3
0 restraints
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.

Refinement. All hydrogen atoms were placed in calculated positions and refined using a riding model. Aromatic C—H distances were set to 0.93\%A and their U(iso) set to 1.2 times the Ueq for the atoms to which they are bonded. Methyl groups were allowed to rotate about the C—C bond and C—H distances were set to 0.96\%A with U(iso) set to 1.5 times the Ueq for the C atoms to which they are bonded. The N—H bond was set to 0.86 Å and Uiso(H) set to 1.2 times Ueq (N).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C11.0844 (6)0.4701 (5)0.30830 (15)0.147 (2)
H1A1.1085190.3937180.3227220.221*
H1B1.0523580.5323440.3289870.221*
H1C1.2095630.4927480.2927180.221*
C20.8982 (5)0.4565 (5)0.27729 (13)0.0941 (12)
C30.8627 (5)0.5421 (4)0.24562 (13)0.0975 (13)
H30.9518600.6097900.2438390.117*
C40.6972 (5)0.5300 (3)0.21623 (11)0.0781 (9)
H40.6759650.5882200.1949050.094*
C50.5657 (4)0.4299 (3)0.21949 (10)0.0599 (7)
C60.5955 (5)0.3451 (3)0.25146 (11)0.0759 (9)
H60.5034240.2789650.2540830.091*
C70.7638 (5)0.3589 (4)0.27974 (12)0.0909 (11)
H70.7856410.3003060.3008900.109*
C80.4691 (4)0.1979 (2)0.16645 (10)0.0658 (8)
H8A0.6100900.2138150.1768770.099*
H8B0.4765560.1651690.1379650.099*
H8C0.4005580.1398250.1848820.099*
C90.3448 (4)0.3143 (2)0.16587 (9)0.0506 (6)
C100.1699 (4)0.3507 (2)0.14252 (9)0.0499 (6)
C110.0454 (4)0.2756 (2)0.11238 (9)0.0544 (7)
C120.1452 (4)0.3207 (2)0.09090 (8)0.0485 (6)
C130.2792 (4)0.2570 (2)0.06385 (8)0.0483 (6)
C140.4553 (4)0.3276 (2)0.04919 (8)0.0468 (6)
C150.4475 (4)0.4479 (2)0.06554 (8)0.0462 (6)
C160.2392 (5)0.1256 (2)0.05188 (12)0.0774 (10)
H16A0.0996020.1020950.0612760.116*
H16B0.2492960.1166660.0213620.116*
H16C0.3430380.0742890.0653710.116*
C170.6339 (4)0.2894 (2)0.02206 (9)0.0535 (7)
C180.6614 (4)0.1593 (2)0.00682 (11)0.0708 (8)
H18A0.7926190.1521840.0087550.106*
H18B0.6637930.1052020.0310400.106*
H18C0.5452540.1376560.0115330.106*
C190.6221 (4)0.6541 (2)0.07278 (8)0.0483 (6)
C200.8126 (4)0.7101 (2)0.06251 (10)0.0622 (8)
H200.9142760.6684190.0464830.075*
C210.8514 (4)0.8282 (3)0.07617 (11)0.0720 (9)
H210.9792940.8658100.0690330.086*
C220.7045 (5)0.8909 (2)0.10002 (10)0.0691 (8)
H220.7329750.9697850.1095680.083*
C230.5159 (5)0.8359 (2)0.10959 (10)0.0708 (9)
H230.4143350.8785050.1253370.085*
C240.4730 (4)0.7178 (2)0.09628 (10)0.0653 (8)
H240.3437070.6814880.1031680.078*
N10.3972 (3)0.4139 (2)0.18886 (7)0.0557 (6)
N20.2643 (4)0.5101 (2)0.17970 (8)0.0674 (7)
N30.1272 (3)0.4702 (2)0.15169 (8)0.0614 (6)
N40.5960 (3)0.53417 (17)0.05747 (7)0.0519 (5)
H4A0.6926430.5114430.0396180.062*
O10.1094 (3)0.16977 (17)0.10657 (8)0.0850 (7)
O20.7730 (3)0.36351 (17)0.01127 (7)0.0678 (6)
S10.23163 (9)0.47131 (5)0.09830 (2)0.0503 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.070 (2)0.251 (6)0.121 (4)0.001 (3)0.031 (2)0.071 (4)
C20.0587 (18)0.149 (4)0.075 (3)0.004 (2)0.0041 (17)0.040 (3)
C30.075 (2)0.134 (3)0.084 (3)0.040 (2)0.018 (2)0.044 (3)
C40.0793 (19)0.090 (2)0.066 (2)0.0208 (18)0.0045 (16)0.0187 (18)
C50.0502 (14)0.0720 (18)0.058 (2)0.0035 (14)0.0001 (13)0.0134 (16)
C60.0725 (18)0.087 (2)0.068 (2)0.0062 (17)0.0122 (16)0.0021 (19)
C70.084 (2)0.115 (3)0.074 (3)0.014 (2)0.0183 (19)0.013 (2)
C80.0622 (16)0.0630 (17)0.072 (2)0.0132 (14)0.0087 (14)0.0003 (15)
C90.0525 (14)0.0490 (14)0.0504 (17)0.0010 (12)0.0005 (11)0.0017 (12)
C100.0511 (13)0.0455 (14)0.0529 (17)0.0047 (11)0.0030 (11)0.0017 (12)
C110.0641 (15)0.0423 (14)0.0567 (19)0.0090 (12)0.0034 (13)0.0030 (12)
C120.0531 (13)0.0364 (12)0.0558 (18)0.0043 (11)0.0017 (12)0.0002 (12)
C130.0536 (13)0.0386 (12)0.0528 (17)0.0000 (11)0.0009 (11)0.0038 (11)
C140.0504 (13)0.0383 (12)0.0518 (17)0.0019 (11)0.0007 (11)0.0044 (11)
C150.0492 (13)0.0400 (13)0.0494 (17)0.0005 (11)0.0014 (11)0.0011 (11)
C160.0778 (19)0.0449 (15)0.109 (3)0.0109 (14)0.0271 (18)0.0228 (17)
C170.0557 (14)0.0493 (15)0.0555 (18)0.0039 (13)0.0006 (12)0.0054 (13)
C180.0740 (18)0.0581 (17)0.080 (2)0.0079 (14)0.0177 (16)0.0171 (16)
C190.0536 (14)0.0363 (12)0.0550 (17)0.0052 (11)0.0055 (11)0.0012 (11)
C200.0556 (15)0.0513 (15)0.080 (2)0.0044 (13)0.0134 (14)0.0078 (14)
C210.0632 (17)0.0551 (17)0.097 (3)0.0184 (14)0.0155 (16)0.0080 (17)
C220.086 (2)0.0438 (14)0.078 (2)0.0183 (15)0.0109 (16)0.0106 (15)
C230.084 (2)0.0466 (15)0.081 (2)0.0089 (14)0.0286 (16)0.0139 (15)
C240.0674 (16)0.0465 (15)0.082 (2)0.0116 (13)0.0253 (15)0.0088 (14)
N10.0520 (11)0.0577 (13)0.0573 (16)0.0025 (11)0.0050 (10)0.0065 (11)
N20.0664 (14)0.0566 (14)0.0792 (19)0.0067 (12)0.0090 (12)0.0127 (13)
N30.0627 (13)0.0518 (13)0.0696 (17)0.0071 (11)0.0129 (12)0.0119 (12)
N40.0520 (11)0.0410 (11)0.0625 (16)0.0040 (10)0.0124 (10)0.0044 (10)
O10.0985 (15)0.0523 (12)0.1039 (19)0.0276 (11)0.0425 (13)0.0197 (12)
O20.0611 (11)0.0579 (11)0.0842 (16)0.0031 (9)0.0205 (10)0.0145 (10)
S10.0548 (4)0.0376 (3)0.0585 (5)0.0043 (3)0.0103 (3)0.0054 (3)
Geometric parameters (Å, º) top
C1—C21.525 (5)C13—C161.504 (3)
C1—H1A0.9600C14—C151.411 (3)
C1—H1B0.9600C14—C171.465 (3)
C1—H1C0.9600C15—N41.351 (3)
C2—C71.363 (5)C15—S11.717 (2)
C2—C31.379 (5)C16—H16A0.9600
C3—C41.392 (5)C16—H16B0.9600
C3—H30.9300C16—H16C0.9600
C4—C51.376 (4)C17—O21.238 (3)
C4—H40.9300C17—C181.509 (3)
C5—C61.374 (4)C18—H18A0.9600
C5—N11.436 (3)C18—H18B0.9600
C6—C71.385 (4)C18—H18C0.9600
C6—H60.9300C19—C241.378 (3)
C7—H70.9300C19—C201.383 (3)
C8—C91.493 (3)C19—N41.404 (3)
C8—H8A0.9600C20—C211.381 (4)
C8—H8B0.9600C20—H200.9300
C8—H8C0.9600C21—C221.368 (4)
C9—N11.344 (3)C21—H210.9300
C9—C101.377 (3)C22—C231.362 (4)
C10—N31.363 (3)C22—H220.9300
C10—C111.473 (4)C23—C241.382 (4)
C11—O11.237 (3)C23—H230.9300
C11—C121.458 (3)C24—H240.9300
C12—C131.380 (3)N1—N21.373 (3)
C12—S11.748 (2)N2—N31.302 (3)
C13—C141.425 (3)N4—H4A0.8600
C2—C1—H1A109.5C13—C14—C17128.7 (2)
C2—C1—H1B109.5N4—C15—C14124.0 (2)
H1A—C1—H1B109.5N4—C15—S1123.54 (18)
C2—C1—H1C109.5C14—C15—S1112.40 (17)
H1A—C1—H1C109.5C13—C16—H16A109.5
H1B—C1—H1C109.5C13—C16—H16B109.5
C7—C2—C3118.1 (3)H16A—C16—H16B109.5
C7—C2—C1121.1 (5)C13—C16—H16C109.5
C3—C2—C1120.8 (4)H16A—C16—H16C109.5
C2—C3—C4121.8 (3)H16B—C16—H16C109.5
C2—C3—H3119.1O2—C17—C14120.7 (2)
C4—C3—H3119.1O2—C17—C18116.8 (2)
C5—C4—C3118.4 (4)C14—C17—C18122.5 (2)
C5—C4—H4120.8C17—C18—H18A109.5
C3—C4—H4120.8C17—C18—H18B109.5
C6—C5—C4120.6 (3)H18A—C18—H18B109.5
C6—C5—N1120.0 (3)C17—C18—H18C109.5
C4—C5—N1119.4 (3)H18A—C18—H18C109.5
C5—C6—C7119.4 (3)H18B—C18—H18C109.5
C5—C6—H6120.3C24—C19—C20119.2 (2)
C7—C6—H6120.3C24—C19—N4124.9 (2)
C2—C7—C6121.5 (4)C20—C19—N4115.9 (2)
C2—C7—H7119.2C21—C20—C19119.7 (3)
C6—C7—H7119.2C21—C20—H20120.1
C9—C8—H8A109.5C19—C20—H20120.1
C9—C8—H8B109.5C22—C21—C20121.0 (3)
H8A—C8—H8B109.5C22—C21—H21119.5
C9—C8—H8C109.5C20—C21—H21119.5
H8A—C8—H8C109.5C23—C22—C21119.0 (3)
H8B—C8—H8C109.5C23—C22—H22120.5
N1—C9—C10104.1 (2)C21—C22—H22120.5
N1—C9—C8123.7 (2)C22—C23—C24121.1 (3)
C10—C9—C8132.1 (2)C22—C23—H23119.4
N3—C10—C9108.9 (2)C24—C23—H23119.4
N3—C10—C11124.3 (2)C19—C24—C23119.9 (2)
C9—C10—C11126.8 (2)C19—C24—H24120.1
O1—C11—C12121.1 (2)C23—C24—H24120.1
O1—C11—C10116.2 (2)C9—N1—N2111.1 (2)
C12—C11—C10122.7 (2)C9—N1—C5129.3 (2)
C13—C12—C11127.6 (2)N2—N1—C5119.6 (2)
C13—C12—S1111.51 (17)N3—N2—N1106.6 (2)
C11—C12—S1120.89 (19)N2—N3—C10109.4 (2)
C12—C13—C14113.3 (2)C15—N4—C19132.0 (2)
C12—C13—C16122.1 (2)C15—N4—H4A114.0
C14—C13—C16124.6 (2)C19—N4—H4A114.0
C15—C14—C13111.2 (2)C15—S1—C1291.53 (11)
C15—C14—C17120.0 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N4—H4A···O20.861.912.605 (3)137
 

Funding information

The project was supported by King Saud University, Deanship of Scientific Research, Research Chairs and Cardiff University.

References

First citationCambridge Soft (2001). CHEMDRAW Ultra. Cambridge Soft Corporation, Cambridge, Massachusetts, USA.  Google Scholar
First citationDheer, D., Singh, V. & Shankar, R. (2017). Bioorg. Chem. 71, 30–54.  Web of Science CrossRef CAS PubMed Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationJiang, Y. & Kuang, C. (2013). Mini Rev. Med. Chem. 13, 713–719.  Web of Science CrossRef CAS Google Scholar
First citationLi, L., Zhao, C. & Wang, H. (2016). Chem. Rec. 16, 797–809.  Web of Science CrossRef CAS Google Scholar
First citationMancuso, R. & Gabriele, B. (2014). Molecules, 19, 15687–15719.  Web of Science CrossRef Google Scholar
First citationMohamed, H. A., Abdel-Wahab, B. F. & El-Hiti, G. A. (2017). Heterocycles, 94, 716–726.  CAS Google Scholar
First citationRigaku OD (2015). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.  Google Scholar
First citationShafran, E. A., Bakulev, V. A., Rozin, Yu. A. & Shafran, Yu. M. (2008). Chem. Heterocycl. Compd, 44, 1040–1069.  Web of Science CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationYamada, M., Takahashi, T., Hasegawa, M., Matsumura, M., Ono, K., Fujimoto, R., Kitamura, Y., Murata, Y., Kakusawa, N., Tanaka, M., Obata, T., Fujiwara, Y. & Yasuike, S. (2018). Bioorg. Med. Chem. Lett. 28, 152–154.  Web of Science CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds