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:

Novel chiral ferrocenylpyrazolo[1,5-a][1,4]diazepin-4-one derivatives - Synthesis, characterization and inhibition against lung cancer cells. A series of novel 2-ferrocenyl-7-hydroxy-5-phenethyl-5,6,7,8-tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepin-4-one derivatives with optical activity (2) was synthesized in the microwave-assisted condition and characterized by means of IR, (1)H NMR and mass spectroscopy, and furthermore confirmed by X-ray analysis of a representative compound (R)-2a. Preliminary biological evaluation showed that some compounds could suppress the growth of A549, H322 and H1299 lung cancer cells. Among the tested compounds, 2b-d were more effective and might perform their action through cell cycle arrest for A549 cell. Whereas these compounds inhibited growth of H1299 and H322 cells by inducing apoptosis. The anti-tumor activities of these compounds were related to the nature of substituents in benzene moiety. In addition, the results indicated also that compounds 2b-d possessed notable cytotoxicity and selectivity for A549 vs H1299 and H322 lung cancer cells.
{"Chemical": ["ferrocenylpyrazolo[1,5-a][1,4]diazepin-4-one", "(1)H", "2-ferrocenyl-7-hydroxy-5-phenethyl-5,6,7,8-tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepin-4-one"]}