Reactions of MoCl5 and MoO2Cl2 with 4-Phenylimidazole-2-thiol and 2-Thiazoline-2-thiol

Reactions of MoCl5/MoO2Cl2 with 4-phenylimidazole-2-thiol/2-thiazoline-2-thiol in CH3CN solvent in 1:1/1:2 molar ratios have been carried out at room temperature. Products obtained MoCl3(C9H7N2S)(CH3CN),[1]; MoCl2(C9H7N2S)(CH3CN), [2]; Mo2OCl4(C9H8N2S)2, [3] and Mo4O2Cl12(C9H7N2S)4, [4]; MoO2Cl3(C3H5NS2)2, [5] and Mo2O4Cl3(C3H5NS2)2, [6] have been analyzed and characterized by elemental analysis, FTIR, 1H NMR and LC-MS techniques. Compounds being moisture and air sensitive, these have been prepared in inert atmosphere using vacuum line and liquid nitrogen cooled traps. Fragments obtained in LC-MS spectra support the formulae derived.

of the compounds observed in LC-MS mass spectra support molecular formulae derived.
M o a n d C l h ave b e e n e s t i m a t e d gravimetrically by oxinate method 29 and silver chloride method 29 , respectively. Other elements were analysed using Thermo Finnigan Elemental Analyzer. Perkin-Elmer 400 FTIR Spectrometer, in KBr disks was used to record spectra in the range 4000 -400 cm -1 . Brucker Avance-II 400 NMR in DMSO-d 6 was used for obtaining 1 H-NMR spectra. WATERS, Q-TOF Micromass LC-MS (UK) was used for LC-MS spectra in the range 0 -1100 m/z. These facilities were availed at SAIF/CIL, Panjab University, Chandigarh (India).

Synthesis of compounds [1]-[6]
Pressure stabilized dropping funnel having teflon stop-cock was connected to a 100 mL flask. For stirring, a magnetic bead was placed in the flask. Apparatus was connected to vacuum line and dried by heating. On cooling, apparatus was flushed with oxygen purged dry nitrogen gas. Known amount of MoO 2 Cl 2 or MoCl 5 was placed in the flask along with dry CH 3 CN solvent. 4-phethylimidazole-2-thiol or 2-thiazoline-2-thiol was placed in equimolar or 1:2 molar amount along with CH 3 CN solvent in dropping funnel. Solution from the dropping funnel was added to MoO 2 Cl 2 or MoCl 5 placed in bottom flask at room temperature with continuous stirring. Compounds thus prepared were filtered under reduced pressure through filtration unit. Compounds prepared have sensitivity to air and moisture. On exposure to air and moisture, their colour changes to blue. All procedures and work up have been done in vacuum line using oxygen purged under dry nitrogen gas. Moisture and oxygen were further removed using liquid nitrogen cooled traps.
Rearrangement and disproportionation have occurred during the reactions. F/R means filtrate/residue yielding the product. , [6 ] Greenish blue (F)

4-Phenylimidazole-2-thiol has S-H peak at 12.15 ppm. No S-H peak has been observed in [1], [2], [3] & [4].
This indicates the absence of S-H group in [1], [2], [3] & [4]. There has been upfield shift of H-5 in all the four compounds. All the ring protons of phenyl group have also shown up field shift in all the four compounds. Presence of CH 3 CN in [1] & [2] has been inferred by the absorptions at 2.05 & 1.98 ppm, respectively.

LC-MS MASS Spectra 42
Fragmentation pattern obtained below has been used to derive the formulae ( Table 6,7). m/z values have been given below of the fragments.    [6], respectively and further, absence of υ(C=N) in [5] & [6], respectively indicate that S-H bond is missing. Bonding of ligand seems to be through S→Mo coordinate bond.
No characteristic S-H chemical shift has been observed in all the six compounds, indicating that either C=S is present or Mo-S is present in these compounds. Presence of CH 3 CN in [1] & [2] has been inferred due to presence of 1 H NMR peak of CH 3 CN in them.
LC-MS spectra support the presence of particular ligands in these compounds and their proposed formulae.

AACKNOWLEDGEMENT
We acknowledge our thanks to SAIF/CIL, Panjab University, Chandigarh (India) for extending us the characterising facility for LC-MS, elemental analysis, 1H-NMR & FTIR.

Conflict of interest
It is declared that the authors have no conflict of interest.