1814104 bme-daco (N,N'-bis(2-mercapto-2-methylpropane)1,5-diazacyclooctane)nickel(II) 2 1814102 bme-daco bismercaptoethanediazacyclooctane derivative 1 1814103 bme-daco N,N'-bis(2-mercaptoethyl)-N,N'-diazacyclooctane 1