Phospholipids have been synthesized that possess a normal 16-carbon chain plus a "defective" chain only 8 or 12 carbons long and terminated with methoxyl, hydroxyl, or carboxyl groups. In addition, dimeric phospholipids have been prepared in which two phospholipid units are joined at position-1 with chains of 22 or 32 carbons while unconnected chains at position-2 are, once again, short and functionalized. These phospholipids are potentially useful for constructing membranes that contain cavities or irregularities and, therefore, are capable of serving as self-assembled host systems in which drugs and other guest molecules are retained and, perhaps, eventually released.