Phosphorus Can Also Be a “Photocopy”

Abstract

The syntheses of benzoxaphospholes and new benzobisoxaphospholes that display blue fluorescence are presented. The latter compounds were accessed by the use of a new precursor, 2,5-diphosphinohydroquinone. The new compounds were fully characterized, including a structural study of 2,6-tert-butylbenzo[1,2-d;4,5-d']bisoxaphosphole. Quantum yields for photoluminescence were determined for a series of compounds. These materials feature bona fide P horizontal lineC p-p pi bonds suitable for conjugated materials having phosphorus as a participatory atom and can thus "photocopy" the properties of other conjugated organic molecules.

Tuning Thiophene with Phosphorus: Synthesis and Electronic Properties of Benzobisthiaphospholes

“…Crystals suitable for X‐ray diffraction analysis were obtained for 13 a by slow evaporation of a toluene solution, whereas compound 13 d crystallized from a mixture of dichloromethane and diethyl ether at −40 °C (Figure 2). The PC bond lengths for 13 a (1.713(5); 1.754(4) Å) and 13 d (1.713(4); 1.756(3) Å) are comparable to the recently reported benzobisoxaphospholes (1.694(1) and 1.782(1) Å) 4e. The SC bond lengths for 13 a (1.721(5); 1.745(5) Å) and 13 d (1.721(4); 1.742(3) Å) are quite similar to the reported SC(sp 2 ) bond lengths for benzobisthiazole 14 (1.736(2); 1.758(2) Å) confirming the aromaticity of the thiaphosphole (Scheme ) 15…”

“…Moreover, DFT calculations predict only a 20 nm redshift in the π–π* transition from 7 a to 13 a . The BBTP derivatives are also significantly redshifted compared to their phosphorus counterpart 16 (Scheme ), which exhibits a π–π* transition at 337 nm 4e…”

Electron‐Rich Aromatic 1,3‐Heterophospholes – Recent Syntheses and Impact of High Electron Density at σ2P on the Reactivity

“…= 420–438 nm), these being increased by the presence of a p ‐(+M)‐substituent such as a methoxy group. High quantum yields, ranging from 57 to 69 %, have been determined for 2‐aryl‐BOPs 18 (type A, R = aryl) 45a,45b. Alkyl groups in the benzene ring (types B and C) or in the 2‐position of 18 diminished the quantum yield 45a,45c.…”

“…High quantum yields, ranging from 57 to 69 %, have been determined for 2‐aryl‐BOPs 18 (type A, R = aryl) 45a,45b. Alkyl groups in the benzene ring (types B and C) or in the 2‐position of 18 diminished the quantum yield 45a,45c. R 2 ‐BBOPs 19 45a,45b and R‐NOPs 20 45d with three linear anellated rings also display lower PL quantum yields (12–26 %), whereas quantum yields as high as 63 and 85 % for Ph 2 ‐NBOP ( 21 )45e and 2,6‐naphthylene‐bis(BOP*) ( 22 type B),45f respectively, should encourage further searching for more extended anellated 1,3‐oxaphospholes.…”

Oxaphospholes and Bisphospholes from Phosphinophosphonates and α,β‐Unsaturated Ketones

“…Recently, benzannelated 1,3-oxaphospholes drew much attention due to their intriguing luminescent properties. 20 1,2-Oxaphospholes have been addressed in a few instances, but remain an almost unexplored type of phosphorus-containing heterocycle due to the absence of reliable synthetic approaches. 21 …”