Arch Pharm Chem Life Sci. 2019;e1900187. wileyonlinelibrary.com/journal/ardp © 2019 Deutsche Pharmazeutische Gesellschaft | 1 of 7 https://doi.org/10.1002/ardp.201900187 Received: 3 July 2019 | Revised: 30 August 2019 | Accepted: 7 September 2019 DOI: 10.1002/ardp.201900187 FULL PAPER New morpholine‐liganded palladium(II) N‐heterocyclic carbene complexes: Synthesis, characterization, crystal structure, and DNA‐binding studies Ferhat Türker 1 | Canbolat Gürses 2 | Duygu Barut Celepci 3 | Aydı n Aktaş 1 | Burhan Ateş 1 | Yetkin Gök 1 1 Department of Chemistry, Faculty of Science, İnönü University, Malatya, Turkey 2 Department of Molecular Biology and Genetics, Faculty of Science, İnönü University, Malatya, Turkey 3 Department of Physics, Faculty of Science, Dokuz Eylül University, Buca, Izmir, Turkey Correspondence Aydın Aktaş, Department of Chemistry, Inonu University, 44280 Malatya, Turkey. Email: aydinaktash@hotmail.com Funding information Inonu University Research Fund, Grant/Award Number: FYL‐2019‐1446; Dokuz Eylül University, Grant/Award Number: 2010.KB.FEN.13 Abstract A series of the morpholine‐liganded palladium(II) complexes (1a–e) bearing N‐heterocyclic carbene (NHC) functionalized by benzonitrile were synthesized. These complexes were synthesized from (NHC)Pd(II)(pyridine) complexes (PEPPSI) and morpholine. The new complexes were fully characterized by using 1 H NMR, 13 C NMR, Fourier‐transform infrared spectroscopy, and elemental analysis techniques. Single‐ crystal X‐ray diffraction was used to determine the structure of a derivative. The DNA‐binding studies of the new (NHC)Pd(II)morpholine complexes were examined using the pBR322 plasmid. The 2,4,6‐trimethylbenzyl derivative compound has the most DNA binding activity. In addition, for the 3‐methylbenzyl derivative compound, oxidation effects were observed at concentrations higher than 100 μg/ml. Also, the molecular and crystal structures of the complex 3‐methylbenzyl derivative compound were recorded by using a single‐crystal X‐ray diffraction method. KEYWORDS DNA binding, N‐heterocyclic carbene, structure elucidation, substituent effect, synthesis 1 | INTRODUCTION Organometallic compounds are used as drugs in the treatment of many diseases, particularly cancer. For example, cisplatin is one of the most widely used drugs in the treatment of cancer. Since the discovery of cisplatin in the late 1960s by Rosenberg et al., [1] studies on the medical applications of organometallic compounds have increased. The discovery of cisplatin allowed the development of other metal‐based cancer drugs and the improvement of cisplatin‐ like drugs. The newly developed organometallic drugs have a less toxic effect and are targeted to overcome drug resistance in cancer. [2] Metal N‐heterocyclic carbene (M‐NHC) complexes are one of the most important classes of these organometallic compounds. In fact, in the early days when the M‐NHC complexes were discovered, chemists focused on the catalytic applications of these complexes. Recently, the number of studies on the catalytic activities of M‐NHC complexes has increased. [3–9] Furthermore, the publication of the studies on the medical applications of M‐NHC complexes containing metals such as Pt, [10,11] Ru, [12,13] Ag, [14,15] Pd, [16,17] Rh, [18] Ir, [19] Ni, [20] and Cu [21] is increasing. Pd(II)NHC complexes, which are one of the most important compounds of M‐NHC complexes, have recently attracted considerable attention. The Pd(II)NHC complexes are noteworthy for their activity in catalytic reactions when compared with other M‐NHC complexes. [3–9] Besides this, significant studies have also been published in the medical applications of Pd(II)NHC complexes. In recent years, studies on medicinal applications such as anticancer, [22,23] antimicrobial and cytotoxicity, [24] antitumor, [25] DNA interaction, [26] and the enzyme inhibition effect [17] have been carried out for Pd(II)NHC complexes. Also, it was reported that NHC complexes had marked inhibition effects on some metabolic enzymes linked to global health diseases. [27–32] The significant outcome of M‐NHC complexes in medical applica- tions is due to the unique electronic and structural properties of the NHC ligands used. NHC ligands have been used as the perfect ligand for