A broad range of chalcogenolate complexes of group 13 and 15 elements have been isolated and studied. Metathesis of AlEt(2)Cl with (THF)LiSeSi(SiMe(3))(3) gave (THF)AlEt(2)[SeSi(SiMe(3))(3)] in good yield. Chalcogenolysis of Al[N(SiMe(3))(2)](3) With 3 equiv of HESi(SiMe(3))(3) (E = Se, Te) afforded Al[ESi(SiMe(3))(3)](3) (E = Se, Te). Treatment of GaCl3 with 3 equiv of (THF)(2)LiTeSi(SiMe(3))3 produced the homoleptic species Ga[TeSi(SiMe(3))(3)](3); likewise, addition of 3 equiv of (DME)LiSeC(SiMe(3))(3) to InCl3 yielded In[SeC(SiMe(3))(3)](3). Reaction of InCl3 with 3 equiv of (THF)(2)-LiSeSi(SiMe(3))(3) produced (THF)In[SeSi(SiMe(3))(3)](3) in low yield. Homoleptic chalcogenolates, In[ESi(SiMe(3))(3)](3) (E = Se, Te) were prepared by chalcogenolysis of InCp(3) (Cp = eta(5)-C5H5). Addition of THF, pyridine, or TMEDA (N,N,N’,N’-tetramethylethylenediamine) to In[SeSi(SiMe(3))(3)](3) gave 1:1 adducts, (L)In[SeSi(SiMe(3))(3)](3) (L = THF, pyridine, TMEDA). Addition of DMPE (1,2-bis(dimethylphosphino)ethane) to In[SeSi(SiMe(3))(3)](3), produced a 1:1 complex In[SeSi(SiMe(3))(3)](3)(DMPE) that was characterized in solution by NMR spectroscopy; attempts to isolate the complex yielded instead the crystalline 2:1 adduct {In [SeSi(SiMe(3))(3)](3)}(2)(u-DMPE), whose X-ray structure was determined. Indium(I) complexes InESi(SiMe(3))3 (E = Se, Te) were isolated from either the metathesis of InCl with (THF)(2)LiESi(SiMe(3))3 or chalcogenolysis with InCp. Likewise, chalcogenolysis with TlCp produced TlESi(SiMe(3))3 (E = Se, Te). Reaction of PCl3 with (THF)(2)LiSeSi(SiMe(3))(3) produced P[SeSi(SiMe(3))(3)](3) in good yield. The arsenic derivative As[SeSi(SiMe(3))(3)](3) was isolated from the reaction of As(NMe(2))3 and 3 equiv of selenol. Similarly, the antimony and bismuth complexes M[ESi(SiMe(3))(3)](3) (M = Sbt E = Se, Te; M = Bi, E = Se, Te) were prepared in good yields by chalcogenolysis with Sb(NMe(2))3 or Bi[N(SiMe(3))(2)](3).Crystallographic data are as follows. Ga[TeSi(SiMe(3))(3)](3): monoclinic, P2(1)/c, Z = 4, a = 24.235(4) Angstrom, b = 13.808(3) Angstrom, c = 18.689(4) Angstrom, beta = 106.424(16)degrees, R = 0.0926, R(W) = 0.0731. In[SeC(SiMe(3))(3)](3): triclinic, P $($) over bar$$ l, Z = 2, a = 13.772(4) Angstrom, b = 13.778(4) Angstrom, c = 16.026(4) Angstrom, alpha = 74.25(2)degrees, beta = 75.27(2)degrees, gamma = 62.12(2)degrees, R = 0.0424, R(W) = 0.0476. {In[SeSi(SiMe(3))(3)](3)}(2)(u-DMPE): triclinic, Pl $($) over bar$$, Z = 2, a = 13.655(3) Angstrom, b = 13.8323(20) Angstrom, c = 18.442(3) Angstrom, alpha = 97.874(13)degrees, beta = 104.066(16)degrees, gamma = 113.708(15)degrees, R = 0.0323, R(W) = 0.0332. P[SeSi(SiMe(3))(3)](3): monoclinic, P2(l)/c, Z = 6, a = 22.706(4) Angstrom, b = 13.959(5) Angstrom, c = 17.619(3) Angstrom, beta = 93.851(14)degrees, R = 0.0554, R(W) = 0.0463.