Raman Vibrational Analysis of Hemoglobin with Rutin

In this study, experimental vibrational frequencies of Hemoglobin, Rutin and the complex of Hemoglobin - Rutin have been investigated. The experimental Raman spectra recorded in 4000-100cm-1 range of the compounds in solid phase have been recorded

Photoconversion of Ag31 to Ag42 Initiated by Solvated Electrons

Light-matter interactions, especially in atomically precise nanomaterials, belong to an unexplored realm of research with potential benefits for the synthesis of materials. Here, we present an interesting light-activated expansion process of an Ag31 nanocluster to an Ag42 analogue, both clusters being protected with 6-(dibutylamino)-1,3,5-triazine-2, 4-dithiol (shortly, TRZ-H2) ligands. The conversion process was initially monitored through UV–vis, revealing that the violet-colored Ag31 got converted to greenish Ag42, exhibiting their characteristic absorption features. High-resolution mass spectrometric studies confirmed that the as-synthesized [Ag31(TRZ)10] with coexisting di- and monoanionic charged species in dichloromethane solution got converted to [Ag42(TRZ)13] with a dipositive charge state. Electrochemical studies revealed the photoresponsive nature of Ag31, and light illumination resulted in transient intermediate clusters covered with solvated electrons, which contributed to the core expansion. Ag31 is NIR-emitting, while Ag42 is red-emitting. The ultrafast transient absorption studies reveal that Ag42 has strikingly short excited-state carrier dynamics than Ag31. The stable excited-state carriers for Ag31 upon photoexcitation also underline the unique electronic characteristics responsible for such light-activated structural evolution.Peer reviewe

Gold Au(I)6 Clusters with Ligand-Derived Atomic Steric Locking: Multifunctional Optoelectrical Properties and Quantum Coherence

Funding Information: This work was supported by the ERC Advanced grant (DRIVEN, ERC‐2016‐AdG‐742829), the ERC grant (834742), the EU H2020‐MSCA‐RISE‐872049 (IPN‐Bio), the Academy of Finland's Centre of Excellence in Molecular Engineering of Biosynthetic Hybrid Materials Research (HYBER, 2014–2019), and Life‐Inspired Hybrid Materials (LIBER, 346108), Academy of Finland project fundings (No. 352900, 314810, 333982, 336144, 352780, 352930 and 353364), FinnCERES and Photonics Research and Innovation (PREIN) flagship programs. The authors acknowledge the provision of facilities and technical support by Aalto University OtaNano – Nanomicroscopy Center (Aalto‐NMC). | openaire: EC/H2020/834742/EU//ATOP | openaire: EC/H2020/742829/EU//DRIVENAn atomically precise ultrasmall Au(I)6 nanocluster where the six gold atoms are complexed by three sterically interlocking stabilizing ligands is reported, allowing a unique combination of efficient third harmonic generation (THG), intense photoluminescence quantum yield (35%), ultrafast quantum coherence, and electron accepting properties. The reaction of 6-(dibutylamino)-1,3,5-triazine-2,4-dithiol (TRZ) with HAuCl4 leads to complexation by thiolation. However, intriguingly, another reduction step is needed to form the centrosymmetric Au(I)6TRZ3 clusters with the multifunctional properties. Here, ascorbic acid is employed as a mild reducing agent, in contrast to the classic reducing agents, like NaBH4 and NaBH3CN, which often produce mixtures of clusters or gold nanoparticles. Such Au(I)6 nanocluster films produce very strong THG response, never observed for nanoclusters. The clusters also produce brilliant single and multiphoton luminescence with exceptional stability. Density functional theory calculations and femtosecond transient absorption studies suggest ultrafast ligand-to-metal charge transfer, quantum coherence with long decoherence time 200–300 fs, and fast propagation of excitation from the core to the surrounding solvent. Finally, novel electron-accepting ground state properties allow p-doping of 2D field-effect transistor devices. Summarizing, the potential of ultrasmall sterically interlocked Au(I) clusters, i.e., complexes allowed by the new sequential reduction protocol, towards multifunctional devices, fast photoswitches, and quantum colloidal devices is shown.Peer reviewe