(R)-2,2μ-Diamino-6,6μ-dimethylbiphenyl, (R)-6,6μ-Dimethyl-2,2μ-diaminobiphenyl, (R)-6,6μ-Dimethyl-1,1μ-biphenyl-2,2μ-diamine, (R)-6,6μ-Dimethyl-1,1μ-biphenyl-2,2μ-diyldiamine