Three new copper(II)-based coordination compounds namely [Cu₂(ib)₄(dmso)₂] (1), [Cu2(ib)4(4-pyca)2] (2), and [Cu3(ib)4(H2tea)2] (3), where Hib = isobutyric acid, 4-pyca = 4-pyridinecarboxaldehyde, H3tea = triethanolamine, have been synthesized and characterized by IR spectroscopy and thermogravimetric studies. Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 adopt binuclear structures where the four isobutyrate ligands bridge the Cu(II) atoms in a paddlewheel dimer. The square-pyramidal coordination surrounding of the Cu(II) atoms is provided by the coordination in the apical position of dmso in 1 or 4-pyca in 2. Compound 3 is a trinuclear linear cluster with Сu(II) atoms connected by bridging carboxylate and triethanolamine ligands. In 3, each Cu(II) ion has a square-bipyramidal environment where six oxygen atoms surround the central Cu(II) atom and five oxygen atoms and one nitrogen atom surround the peripheral atoms of Cu(II). Hirshfeld surface analysis was employed to elucidate the nature of intermolecular interactions within the crystal lattice. The results indicated a predominance of H···H contacts, accompanied by significant H···O/O···H interactions, suggesting the presence of hydrogen-bonding networks that contribute to the stabilization and packing of the complexes. The synthesized compounds were evaluated in vitro against the oncogenic bacterium Rhizobium (Agrobacterium) vitis, which is responsible for plant tumor formation. The results suggest that these compounds exhibit antibacterial activity, opening prospects for their use in plant protection.