GeWu (to investigate things/affairs, 格物) represents the starting point among the eight clauses (八目) of the Great Learning (Daxue, 大学) in the chapter of The Book of Rites (Lǐ Jì, 礼记) that plays an essential in the Chinese culture of Confucianism. It suggests the importance of investigation and inquiry in gaining insight into both human being and nature world. Historically, GeWu studies have evolved through three significant stages, marked by the contributions of the Xi Zhu (1130 – 1200), Yangming Wang (1472 – 1529) and Chinese modern physicists represented by Samuel C. C. Ting (1936 – ). The concept of GeWu ZhiZhi (to extend knowledge/understanding, 致知) intrigued our minds and motivations revolve around the question — how to create molecular systems and pave the way for new advancements in intelligent chemistry and aware materials, ushering in an era of consciousness. Consequently, we have designed gridofluorenes with the same pronunciation as GeWu for the exploration of the molecular worlds using the fluorenes as building blocks in 2014. Eventually, research results indicated that we created a great family of molecular being with the trans-dimensional extension and cross-scale expansion features on our dream journey from carbon atoms to intellibots.

Scheme 1. The chemical structures of cis-cis-triangle windmill-type gridofluorenes with a rare intramolecular multiple H^...H interaction.

     From science point of view, organic quantum grid dots represent a potentially versatile nanomolecular platform for the processing functionalities of electron, photon, charge, ion as well as molecule. One of them is the Organic NanoHydroCarbons (ONHCs), which enable the precise cross-scale structure-performance relationship due to their covalent networks of hydrogen and carbon atoms. They have many advantages with easily editing and diversity with regards to chemical family of the nanocarbons, in which some carbon allotropes do not strictly consist of the pure carbon atoms because they have the edge with the molecular hydrogens or other atoms as the capping end. Nevertheless, there is a huge space to explore the ONHCs that benefit not only from the science and art but also molecular engineering and integration technology for advanced materials or molecular nanosystems. However, ONHCs as an alternative molecular platform for ultraviolet-emitting wide bandgap semiconductors faces challenges. Herein, we exhibit the critical progress in the circularly polarized ultraviolet-emitting luminescence from the world's smallest chiral gridofluorenes that belong to the newborn of organic stereo-molecular nanohydrocarbons (Scheme 1).

Figure 1. One type of gridofluorenes with circularly polarized luminescence, solid state, EL devices and the statistical data of organic ultraviolet-emitting devices

    To address the aforementioned situation, we established a straightforward and effective strategy to interrupt the π-conjugation and reduce the strain energy of the molecular skeleton by subtle integrating Csp³ into the molecular gridarenes. Simultaneously, the windmill-type nanogrids were transformed into a 3-dimensional non-planar stereo-configuration to strengthen intramolecular H^...H interaction and to suppress intermolecular π-π stacking forces due to the unique super-hindrance effect. Subsequently, we explored the C-H bond activated gridization to produce highly diastereoselective nanohydrocarbons. This innovative gridofluorenes not only enables ultraviolet emission (at a peak of 356-393 nm) and a significant luminescence dissymmetry factor (|g_PL|=0.012) but also achieves the highest external quantum efficiency of 4.17% (λ_EL=386 nm, CIE: 0.17, 0.04) in the undoped UV OLEDs (Figure 1). These results offer a viable pathway for tuning strained semiconductors with circularly polarized ultraviolet luminescence that remark the current pinnacle of efficiency for UV OLED based on the pure molecular nanohydrocarbons. Gridization open a way to the molecular design principle of π-backbones with low reorganization energy and high non-conjugated super-hindrance for creating organic quantum nanomaterials.

     Perceptively, according to the MEICism theory, molecular integration technology offers the molecular editable nano-scaffolds for the molecular systems and organic devices that face the flexible electronic neurobots towards the era of consciousness.