A new mixed complex ion, [Cu(P207)(NH3)2]2-has been identified and its equilibrium with [Cu(P2C>7,)2]6-has been investigated in solutions containing moderate excesses of pyrophosphate ions and ammonia. The logarithm of its complexity constant is 14.22 ± 0.15 and its maximum molar extinction coefficient at 650 µ is 27.0 mole-1 cm.-1. In pyrophosphate and ammonia-deficient solutions, the complex dissociates stepwise to form [Cu(P207)(NH3)]2~a nd [Cu(P207)]2-. The neutral complex [Cu2(P207)(NH3)4]°w as detected in very dilute solutions having the corresponding ratios of its constituents.

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A colorimetric and fluorescent sensor was developed based on 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) for the detection of trace amounts of water in polar organic solvents. Fluorescence and UV-visible absorption spectra of HPTS were measured in a variety of organic solvents (DMF, DMSO, ethanol, methanol). Fluorescence maxima comparable with maximum/minimum ratios were determined by using UV-visible absorption spectroscopy. The HPTS sensor exhibits high sensitivity for water with a detection limit as low as 0.0001 to 0.0005 wt-%. In addition, naked-eye inspection of solutions of HPTS sensor in organic solvents before and after addition of water showed dramatic changes in colour from blue to green. These findings can be applied in the use of HPTS as a molecular probe for trace amounts of water in organic solvents.