Related Experiment Video
Updated: Mar 28, 2026
In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions
Published on: June 16, 2014
Shifting the Paradigm: Acetylene Ligand in Unlocking Unique Cluster Nodes in Silver Cluster Assembled Materials and
Dayona Aleyamma Varghese1, Priyanka Chandrashekar1, Bhawna Kamboj2
1School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram 695551, Kerala India.
Abstract:
Two-dimensional (2D) cluster-assembled materials are unique due to their exceptional optoelectronic and photoluminescence properties. The design and synthesis of 2D materials, where clusters serve as nodes interconnected by conjugated linkers, could significantly enhance the coupling between the nodes, thereby facilitating efficient charge transfer. We have synthesized a novel 2D alkynyl-ligand protected cluster assembled material (CAM) consisting of two distinct types of Ag14 nodes, which are interconnected by pyrazine molecules to form the overall architecture. The presence of two different geometries within the same CAM structure is a rare observation. The formation of this structure could be attributed to the specific bonding interaction between the acetylene ligand and the silver ions. Combined experimental and theoretical calculations revealed that electronic excitation is primarily driven by mixed transition characters. These include π → π* transitions, where electron transfer occurs from occupied C-p orbitals to the vacant π* orbitals of the alkynyl carbon or pyridyl nitrogen atoms, as well as LMCT (Ligand-to-Metal Charge Transfer) transitions mixed with cluster-centred states.
Related Concept Videos
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:37Structure and Physical Properties of Alkynes
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The...
01:26Variables Affecting Phosphorescence and Fluorescence
02:51Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...