Bis-cyclometallated Ir(III) complexes containing 2-(1H-pyrazol-3-yl)pyridine ligands have been synthesised. Their absorption is almost unchanged with changes in pH however the emission intensities vary by a factor of up to three...

Six pyridylideneamine (PYE)‐containing bidentate ligands and their bis‐cyclometallated Ir(III) complexes have been synthesised and fully characterised. The PYE groups show a contribution from a neutral imine resonance form and a zwitterionic pyridinium form. NMR spectroscopy of the para‐substituted ligands and complexes show those with a C6H4 bridging group have the fastest PYE rotation. X‐ray crystallography of p‐1 and p‐3 shows the PYE N‐donor is trigonal planar whereas for the ortho‐complexes it is more pyramidalized implying an increased contribution of the zwitterionic resonance form for the ortho‐complexes.

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A fast and sensitive chromatographic RP–HPLC technique for examining tramadol hydrochloride (TRM-HCl) in tablets through using fluorescence detection (FL-D) and ultraviolet detection (UV-D) is reported in this paper. The separation was carried out using the reverse phase method on a Brownlee BIO C18 analytical column with a mobile phase consisting of 0.1% acetic acid and acetonitrile (2.5:7.5 v/v), which was pumped with an isocratic elution at a flow rate of 1 ml/min. The LOD and LQD values obtained in the current study indicate that FL-D is more sensitive, and hence preferable to UV detectors in the quantification of TRM-HCl tablets over the entire concentration range used (5-125 µg/ml). The study showed that the mean percentage recoveries from five samples were 99.93-100.023% (FL-D), which is somewhat similar to that of the UV-D (99.93-100.028). In conclusion, although Fl-D is acceptable for the quantification of tramadol tablets, UV-D offers higher detection sensitivity and reproducibility, particularly within concentrations that are low in the deposit collectors.