You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

The photophysics of 7-(N,N'-diethylamino)coumarin-3-carboxylic acid in water/AOT/isooctane reverse micelles: an excitation wavelength dependent study. In this manuscript we have studied the photophysics of 7-(N,N'-diethylamino)coumarin-3-carboxylic acid (7-DCCA) in water/AOT/isooctane reverse micelles. For this purpose we have used steady state absorption and fluorescence emission spectroscopy and time resolved fluorescence spectroscopy. We have studied the spectral behaviour of 7-DCCA inside the water/AOT/isooctane reverse micelles with variation of excitation wavelength. We have studied the dynamics of solvent and rotational relaxation by using two different excitation wavelengths (λ(exi) = 375 nm and λ(exi) = 405 nm). We have observed the excitation wavelength dependent dynamics of 7-DCCA in the reverse micelles. The fluorescence quantum yield, decay time, solvent relaxation time and rotational relaxation time of 7-DCCA in reverse micelles vary with the excitation wavelength. A two step and wobbling-in-cone model was used to interpret the rotational relaxation dynamics of 7-DCCA in reverse micelles.
{"Chemical": ["AOT", "7-(N,N\u0027-diethylamino)coumarin-3-carboxylic acid", "isooctane", "7-DCCA"]}