  The search for new superconducting compounds with higher critical
temperatures $T_{c}^{\prime}$s has long been the very heart of scientific
research on superconductivity. It took 75 years for scientists to push the
$T_{c}$ above liquid nitrogen boiling temperature since the discovery of
superconductivity. So far, the record high $T_{c}$ of about 130 K at atmosphere
pressure was reported in some multilayer Hg(Tl)-Ba-Ca-Cu-O compounds.
Meanwhile, sulfur hydride system holds the highest $T_{c}$ of around 200 K at
high pressure of about 150 GPa. While keeping these records for
superconductivity, either the toxicity of these superconductors or the
requirement of extreme pressure condition for superconductivity limits their
technology applications. Here we show that doping a chain link molecule $-$
$p$-terphenyl by potassium can bring about superconductivity at 123 K at
atmosphere pressure, which is comparable to the highest $T_{c}$ in cuprates.
The easy processability, light weight, durability of plastics, and
environmental friendliness of this kind of new superconductor have great
potential for the fine-tuning of electrical properties. This study opens a
window for exploring high temperature superconductivity in chain link organic
molecules.
