It seems like you're asking about the chemical formula for a material called "Mandarin of membran." However, there is no known chemical compound or material with this name.

It's possible you've misheard or misspelled the name. Could you clarify what you're looking for? Maybe you're thinking of:

* A specific type of fruit? "Mandarin" usually refers to a type of citrus fruit.

* A material used in a specific industry?

* A fictional material?

Please provide more context, and I'll do my best to help you find the chemical formula you're looking for!