Treatment of the gold(I) halide complexes LAuCl (L = PMe3, PPh3, CNC6H3MC2-2,6) with K[Ph2P(Se)NP(Se)-Ph-2] provides the gold-selenium coordination compounds [{N(Ph2PSe)(2)-SeSe ' }AuL]. However, on standing for a number of days, the complex [{N(Ph2PSe)(2)-Se,Se ' }AuPMe3] gains a phosphine, to provide the bis(phosphine) species [{N(Ph2PSe)(2)-Se,Se ' }Au(PMe3)(2)]. Treatment of the K[Ph2P(Se)NP(Se)Ph-2] ligand with [(Ph3PAu)(3)O]-BF4 allows the isolation of [{N(Ph2PSe)(2)-SeSe '}(AuPPh3)(2)]BF4. Reaction of the complex [(dppm)(AuCl)(2)] with AgSO3CF3 followed by addition of the ligand K[Ph2P(Se)NP(Se)Ph-2] results in the formation of [{N(Ph2PSe)(2)- Se,Se ' }Au-2(dppm)]OSO2CF3 and treatment of [(tht)AuCl] (tht = tetrahydrothiophene) with an equimolar quantity of K[Ph2P(Se)NP(Se)Ph-2] affords the complex [{N(Ph2PSe)(2)-SeSe '}(2)Au-2]. The compounds [{N(Ph2PSe)(2)-Se,Se ' }Au-2(dppm.)]OSO2CF3. [{N(Ph2PSe)(2) -Se,Se ' }AuPPh3] and [{N(Ph2PSe)(2)-Se,Se ' }Au(PMe3)(2)] have been investigated crystallographically. The results reveal that the metal centers are two-, three-, and four-coordinate, respectively. The cationic, eight-membered ring complex bearing the dppm ligand displays transannular aurophilic bonding and is further associated into dimers via intermolecular gold-selenium contacts. The six-membered rings in the other two structures have C-2-symmetrical twist conformations, however, the Au(I) coordination sphere in [N(PPh2Se)(2)]AuPPh3 is not fully symmetrical. The Au-Se bond lengths increase dramatically as the coordination number of the metal atom becomes larger.