Four new heteroleptic mononuclear complexes, [Cu(PPh₃)₂L¹](1) {L¹ = (C₉H₁₁O₂CS₂^–), [2‐(4‐methoxyphenyl)ethyl]xanthate}, [Cu(PPh₃)₂L²] (2) [L² = (C₆H₇OCS₂^–), benzylxanthate], [Cu(PPh₃)₂L³] (3) [L³ = (C₅H₉OCS₂^–), (cyclobutylmethyl)xanthate] and [Cu(PPh₃)₂L⁴] (4) [L⁴ = (NC₁₃H₁₃NCS₂^–), N‐benzyl‐N‐(4‐pyridylmethyl)dithiocarbamate], have been synthesized and characterized by using microanalysis, IR, UV/Vis, ¹H, ¹³C and ³¹P NMR spectroscopy and X‐ray crystallography; their photoluminescent behaviour and molecular electrical conductivity have been investigated. Cu^I possesses four‐coordinate distorted tetrahedral geometry in all the complexes. All are weakly conducting and exhibit semiconductor behaviour in the studied 303–363 K temperature range. Complex 4 shows striking luminescent behaviour emitting bluish green light at 480 nm in CH₂Cl₂ solution at room temperature.