Luminescent Re(I) scorpionates supported by tris(2-pyridyl)phosphine and its derivatives

A series of luminescent Re(I) scorpoinates has been synthesized by treatment of Re(CO)(5)Br with tris(2-pyridyl) phosphine (Py3P) as well as its oxide or sulfide (Py3P=O and Py3P=S). The reaction of Re(CO)(5)Br with Py3P affords a neutral [Re(CO)(3)(N,N'-Py3P)Br] complex, isolated as two polymorphs. The Py3P=X (X = 0 or S) ligands under the same conditions produce cationic scorpionates of [Re(CO)3(()N,N',N-Py3P=X)]Br type, wherein N,N', N-coordination takes place. At ambient temperature, the above compounds exhibit solid state phosphorescence of (3)(M + L')LCT character (L = Py3P = X, L' = CO) with lambda(max) = 540 nm for [Re(CO)(3) (Py3P)Br] and 490 nm for [Re(CO)(3)(Py3P=X)]Br, the lifetime ranging 22-42 mu s. Moreover, thermochromic luminescence is inherent in these complexes that is manifested as a green to blue and changing its color upon cooling from 300 to 77 K. The spectral and electrochemical properties of the complexes obtained are also discussed.

Automated summary

A series of luminescent Re(I) scorpoinates have been successfully synthesized, exhibiting solid state phosphorescence at ambient temperature and thermochromic luminescence upon cooling. The compounds also display interesting spectral and electrochemical properties.