Barium's 3D Crystal Maze: A New Metal-Organic Framework Explained

Scientists have created a cool new 3D crystal structure using barium and a special acid. This structure, called a metal-organic framework (MOF), is built from long, rod-like building blocks. These blocks are connected by a type of acid called terephthaloylbis(azanediyl)diacetic acid, or TPBA for short. The barium ions in the structure are linked together by water molecules and parts of the acid, forming a chain-like pattern. These chains then join together to make the 3D MOF. The MOF has a unique feature where two of these structures intertwine, like a double helix. This intertwining is held together by special bonds called dihydrogen bonds and some other types of interactions between the atoms. The scientists also found that the MOF glows under certain conditions, which is a neat property to study further. To understand how the atoms in the MOF interact, the scientists used a technique called Hirshfeld surface analysis. This helps them see which atoms and bonds are the most important in holding the MOF together. They found that hydrogen and oxygen bonds play a big role, along with some other specific interactions.