M 7712 (OTTO) Manganese(II) phthalocyanine Cas 14325-24-7 - used as a coating of quartz crystals which is to be used as sensors for detecting H2S. M 7712 (OTTO) Manganese(II) phthalocyanine Cas 14325-24-7- used to discriminate between cheese varieties, detect volatile hazardous compounds and spoilt fruit.