Hydrogen sulfide is an extremely dangerous gas: it is enough that it represents 0.002-0.005% of the volume of the air to endanger the life of those who come into contact with it. Currently, carbon dioxide represents approximately 0.04 % of the volume of the Earth's atmosphere, if hydrogen sulfide represented 1 %, it would be 25 times the volume of carbon dioxide! This would bring terrible consequences for the ecosystem on our planet, as you can imagine. Another danger is the fact that hydrogen sulfide is flammable, therefore, a high concentration of this gas in an atmosphere with some oxidant (oxygen, chlorine, fluorine, etc.) is not a good idea. In addition, when dissolved in water, it forms a weak acid, and assuming your planet has bodies of water on its surface and clouds of water in its sky, like in our planet, that would make them acidic. But this would be worse if that 1 % now corresponded to hydrogen chloride, since it forms a strong acid in aqueous solution. Hydrogen fluoride is neither an option: it is also very corrosive.
Ammonia has an acidity comparable to that of carbon dioxide, but dissolves in water to form a strongly alkaline solution (ammonium hydroxide). Imagine a lake contaminated with ammonium hydroxide, in the worst case, its pH would be greater than 10, which means that the only living beings that would be able to survive in it, would be alkaliphiles.
All these compounds would be dangerous for life on Earth if they represented 1 % of the atmospheric composition. But if your planet is inhabited by extraterrestrial life forms, perhaps they would have evolved to interact with them without problems. If you want to incorporate into the atmosphere of your planet a certain compound that interacts with native life, it will be very different from Earth's, especially if you choose any of these compounds.
You can consult this list of molecules detected in interstellar space so far, you could choose any of them to fill in that missing space in the atmospheric composition of your planet. Carbon dioxide represented a more significant fraction of the Earth's primitive atmosphere, but the plants evolved to use it metabolically and ended up reducing it, something similar could happen on your planet, just make sure that the compound is abundant in interstellar space, while simpler better.