Multifunctional Quaternary Phosphorus/Bromoargentate Hybrids: The Achievement of Greenish Blue Luminescence, Repeatable Photocurrent Responses and Durable Antimicrobial Activities with Enhanced Water Stability

BACKGROUND: The realization of multifunction in one bulk material is fascinating for developing a new generation of devices. Quaternary phosphorus salts were seldom utilized as templates in haloargentate systems, and the hybridization of alkyl(triphenyl)phosphonium with halometallate will be a good strategy for the development of multifunctional material, especially for biological material. METHODS: Under the template of (triphenyl)phosphonium-based quaternary phosphorus salts with different spacer lengths (n=2, 3, 4), three bromoargentate hybrids were constructed via the solution method, ie, (1,2-DBTPP)(Ag(2)Br(4)) (1), {(1,3-DBTPP)(2)(Ag(7)Br(11))]∙CH(3)CN∙H(2)O}(n) (2), and {[(1,4-DBTPP)(Ag(5)Br(7))](CH(3)CN)(2)∙H(2)O}(n) (3) (1,2-DBTPP(2+)=ethane-1,2-diylbis (triphenyl)phosphonium, 1,3-DBTPP(2+)=propane-1,3-diylbis (triphenyl)phosphonium, 1,4-DBTPP(2+)=butane-1,4-diylbis (triphenyl)phosphonium)). RESULTS: The (Ag(7)Br(11))(n)(4n-) chain in 2 is a new type of 1-D bromoargentate chain constructed from cubane-like Ag(4)Br(4) nodes, AgBr(4) tetrahedrons and AgBr(3) triangles. Interestingly, by elongating spacer n from 2 to 4, argentophilicity interactions are weakened, and the hydrogen bonds are strengthened. Consequently, their water stabilities and photocurrents are improved, in which the Ag-4d/Br-4p to π* anti-bonding orbital of the quaternary phosphorus transfer is facilitated. Furthermore, the greenish blue emissions can be detected. Finally, high inhabitation rates against Streptococcus mutans and Candida albicans can be observed in 2 and 3. CONCLUSION: In all experiments, by elongating the spacer lengths of quaternary phosphorus salts, multifunctions were integrated in the quaternary phosphorus/bromoargentate hybrids, including greenish blue luminescence, repeatable photocurrent responses and durable antimicrobial activities with enhanced water stability. This work could provide a theoretical guide for the design of new biologically multifunctional materials.