UNUSUAL BONDING IN A MAIN-GROUP MULTIPLE-BONDED SYSTEM - UMBRELLA-SHAPED DIPHOSPHENES BUSCH, T BUSCH T Schoeller, Wolfgang Schoeller Wolfgang NIECKE, E NIECKE E NIEGER, M NIEGER M WESTERMANN, H WESTERMANN H 28 24 4334-4340 4334-4340 AMER CHEMICAL SOC 1989