β‐Meso Covalently linked AzaBODIPY‐Pd(II) Dipyrrin Conjugate

Abstract

The first example of azaBODIPY‐metal dipyrrin conjugate such as covalently linked azaBODIPY‐Pd(II) dipyrrin conjugate where the meso‐carbon of Pd(II) dipyrrin moiety was linked to β‐pyrrole carbon of azaBODIPY moiety was synthesized over sequence of facile steps under simple reaction conditions. The compound azaBODIPY‐Pd(II) dipyrrin conjugate is freely soluble in common organic solvents and characterized by HR‐MS, 1D & 2D NMR, X‐ray crystallography, absorption, fluorescence and electrochemical techniques. The X‐ray structure revealed that the azaBODIPY and Pd(II) dipyrrin moieties are almost orthogonal to each other with a dihedral angle of 80°. The spectral and electrochemical studies supported weak interaction between azaBODIPY and Pd(II) dipyrrin moieties in conjugate and marginally influences each other's electronic properties.

Dipyrrin based metal complexes: reactivity and catalysis

“…The Suzuki-Miyaura cross-coupling is an important tool in organic chemistry with active research in the development of new palladium catalysts. 135 Surprisingly, while homo-and heteroleptic Pd(II) dpm complexes have been extensively investigated, 33,[136][137][138][139][140][141][142][143][144][145] only one report described the potential of these compounds for C-C bond formation. 140 Mono-and bi-nuclear heteroleptic complexes 64 and 65 (Fig.…”

Current Advances in the Synthesis of Valuable Dipyrromethane Scaffolds: Classic and New Methods

“…Ravikanth’s research group reported the preparation and characterization (structural, photophysical and electrochemical) of β-meso covalently linked azaBODIPY/BODIPY dyad 64 [65] and Pd(II) azaBODIPY/dipyrromethene complex 65 [66,67]. The unconditionally required dipyrromethane-substituted azaBODIPY intermediary 63 was synthesized in reasonable yield by stirring a dichloromethane solution of 2-formyl azaBODIPY 62 , and surplus pyrrole, at room temperature, under boron trifluoride diethyl etherate catalysis and inert atmosphere conditions (Scheme 14).…”

Synthesis, X‐ray Structure, Spectral and Electrochemical Properties of Aza‐BODIPY‐Metal Dipyrrinyl Conjugates

“…The distortion in aza‐BODIPY core is minimal and out of four phenyl rings, two phenyl rings make a dihedral angle of 42° and 65° respectively to the aza‐BODIPY core which is probably a consequence of the steric bulk of the phosphine ligand. The average B−N, N2‐C4 and N2‐C5 distances in compound 1 remain almost same as in our earlier reported compound aza‐BODIPY−Pd(II) dipyrrinyl . In compound 1 , the Re(I) dipyrrinyl unit was in perpendicular oritentation to the aza‐BODIPY unit and forms a dihedral angle of 89° with the aza‐BODIPY unit (Figure b).…”

“…In compound 1 , the Re(I) dipyrrinyl unit was in perpendicular oritentation to the aza‐BODIPY unit and forms a dihedral angle of 89° with the aza‐BODIPY unit (Figure b). This clearly suggests that Re(I) metallation results in more perpendicular orientation of Re(I) dipyrrinyl unit to aza‐BODIPY unit in compound 1 unlike the reported aza‐BODIPY−Pd(II) dipyrrinyl complex where the Pd(II) dipyrrinyl and aza‐BODIPY moieties were oriented by 67.65° with each other …”

“…Thus, covalently linking of metal dipyrrinyl complex to the light absorbing unit such as aza‐BODIPY would result in bichromophoric system that will enhance the excited state energy to the triplet state and such bichromophoric systems would have applications in electroluminescence, luminescent molecular probes, photocatalysis, triplet‐triplet annihilation up‐conversion and so on. A perusal of literature reveals that the reports on BODIPY‐metal dipyrrinyl, and aza‐BODIPY‐metal dipyrrinyl systems are very few to explore the potential of such bichromophoric systems for various applications. Herein, we report the synthesis, structure, spectral and electrochemical properties of three novel aza‐BODIPY‐metal dipyrrinyl (Re(I), Ni(II) and Zn(II)) bichromophoric systems 1–3 (Figure ).…”