Chloro(trimesitylphosphine)gold(I), [AuCl(C9H11)P3],
has approximate threefold symmetry in the solid state [dihedral angles between the mesityl ring planes and the relevant Au--PnC planes are 47.0(1), 48.0(1) and
48.5 (1)°]. The Au atom has a linear coordination geometry
with AumC1 and Au--P bond lengths of 2.2716 (19)
and 2.2634 (15) A, respectively, and a PmAu--C1 bond
angle of 178.01 (8) °. The Ca~--Ca~ bond lengths are in
the range 1.360 (10) to 1.424 (8) ,4,, while the range of
Car--Csp3 distances lies between 1.499(10) and
1.529 (9) A.