Rasyn

Rasyn develops industrial chemicals against a customer’s performance and process requirements — new compounds, new formulations, and improvements to existing chemistry — across cooling, catalysis and crystal design. Most industrial products are formulations: a datacenter coolant is a mixture of around ten ingredients, and there are more possible mixtures than anyone could test.

Its models cover retrosynthesis, reaction prediction and spectral analysis, paired with experimental testing, compressing a development cycle that normally runs three to five years. The team has invented, synthesized and patented three new chemicals, including a PFAS-free datacenter coolant, and licenses the resulting chemistry to manufacturers. Its Marigold platform runs any chemistry task from a plain-language request.

Rasyn is in Y Combinator’s Summer 2026 batch, and Array invested in its 2026 pre-seed.