Phosphine-Coordinated Pure-Gold Clusters: Diverse Geometrical Structures and Unique Optical Properties/Responses

Synthetic techniques, geometrical structures, and electronic absorption spectra of phosphine-coordinated pure-gold molecular clusters (PGCs) accumulated over 40 years are comprehensively collected especially for those with unambiguous X-ray crystal structures available. Inspection of the electronic absorption spectra from geometrical aspects reveals that their optical properties are highly dependent on the cluster geometries rather than the nuclearity. Recent examples of unusual clusters that show unique color/photoluminescence properties and their utilization for stimuli-responsive modules are also presented

Laser/Light Applications in Neurology and Neurosurgery

Applications of light in neurology and neurosurgery can be diagnostic or therapeutic. Neurophotonics is the science of photon interaction with neural tissue. Photodynamic therapy (PDT) has been attempted to destroy infiltrative tumor cells in tissue. Spatially modulated imaging (MI) is a newly described non-contact optical technique in the spatial domain. With this technique, both quantitative mapping of tissue optical properties within a single measurement and cross sectional optical tomography can be achieved rapidly. The ability to control the activity of a defined class of neurons has the potential to advance clinical neuromodulation

A grand unified model for liganded gold clusters

A grand unified model (GUM) is developed to achieve fundamental understanding of rich structures of all 71 liganded gold clusters reported to date. Inspired by the quark model by which composite particles (for example, protons and neutrons) are formed by combining three quarks (or flavours), here gold atoms are assigned three ‘flavours' (namely, bottom, middle and top) to represent three possible valence states. The ‘composite particles' in GUM are categorized into two groups: variants of triangular elementary block Au(3)(2e) and tetrahedral elementary block Au(4)(2e), all satisfying the duet rule (2e) of the valence shell, akin to the octet rule in general chemistry. The elementary blocks, when packed together, form the cores of liganded gold clusters. With the GUM, structures of 71 liganded gold clusters and their growth mechanism can be deciphered altogether. Although GUM is a predictive heuristic and may not be necessarily reflective of the actual electronic structure, several highly stable liganded gold clusters are predicted, thereby offering GUM-guided synthesis of liganded gold clusters by design