[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule appears as a colorless crystalline solid, or a dark-brown liquid. Strongly irritating to skin and eyes. Toxic by ingestion and inhalation. Used as a military poison gas."}, {"from": "gpt", "value": "[C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][As][Branch1][=Branch2][C][=C][C][=C][C][=C][Ring1][=Branch1][Cl]"}]