Substituted diaryl or diheteroaryl methanes, ethers and amines having retinoid agonist, antagonist or inverse agonist type biological

A compound of the formula

• where
• R4is H or F;
• R2 is fluoro-substituted alkyl of 1 to 6 carbons, NO2, NH2, COOC1-6alkyl, N3 or I;
• R4* is H, F, NO2 or NH2;
• Z is —C≡C—, —CH═CH—, —CO—NH—, or —COO—;
• X3 is CH and
• R8 is H, lower alkyl of 1 to 6 carbons, tri(lowerC1-6alkyl)lsilyl-lowerC1-6alkyl, benzyl, or a pharmaceutically acceptable salt of said compound.