Highly packed polycationic ammonium, sulfonium and phosphonium lipids

A compound having the formula:

• and salts thereof where:
• X is N;
• x is an integer ranging from 1 to about 20;
• ni, where i=1 to x, are, independently of one another, integers that can have a value ranging from 1 to about 6;
• r is 0 or 1;
• with N being positively charged when r is 1;
• RA and RB, independently of one another, are selected from the group consisting of H, or an alkyl, hydroxyalkyl or thiol-substituted alkyl group having from 1 to 6 carbon atoms;
• R1 and R2, independently of other R1 and R2, is selected from the group consisting of alkyl groups having from 1 to about 6 carbon atoms;
• and
• A1 and A2, independently of other A1 and A2 groups, are selected from the group consisting of straight-chain or branched alkyl groups substituted with one or two NH2 or amine groups within about 3 carbon atoms of the bond between A1 or A2 and X.