{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T19:11:05Z","timestamp":1777403465314,"version":"3.51.4"},"reference-count":43,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,1,20]],"date-time":"2024-01-20T00:00:00Z","timestamp":1705708800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>In the process of systematically studying the methylhydroxyiminoethaneamide bis-chelate ligands with polymethylene spacers of different lengths, L1\u2013L3, and their transition metal complexes, a number of new Ni(II) and Cu(II) species have been isolated, and their molecular and crystal structures were determined using single-crystal X-ray diffraction. In all of these compounds, the divalent metal is coordinated by the ligand donor atoms in a square-planar arrangement. In addition, a serendipitously discovered new type of neutral Ni(II) complex, where the propane spacer of ligand L2 underwent oxidation to the propene spacer, and one of the amide groups was oxidised to the ketoimine, is also reported. The resulting ligand L2\u2032 affords the formation of neutral planar Ni(II) complexes, which are assembled in the solid state on top of each other, and yield two polymorphic structures. In both structures, the resulting infinite, exclusively parallel metal ion columns in ligand insulation may serve as precursor materials for sub-nano-conducting connectors. Overall, this paper reports the synthesis and characterisation of seven new anionic, cationic, and neutral Ni(II) and Cu(II) complexes, their crystal structures, as well as experimental and computed UV\u2013Vis absorption spectra for two structurally similar Ni(II) complexes, yellow and red.<\/jats:p>","DOI":"10.3390\/molecules29020522","type":"journal-article","created":{"date-parts":[[2024,1,22]],"date-time":"2024-01-22T11:36:41Z","timestamp":1705923401000},"page":"522","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Old Acquaintances and Novel Complex Structures for the Ni(II) and Cu(II) Complexes of bis-Chelate Oxime\u2013Amide Ligands"],"prefix":"10.3390","volume":"29","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4602-0405","authenticated-orcid":false,"given":"Carla","family":"Bazzicalupi","sequence":"first","affiliation":[{"name":"Department of Chemistry \u201cUgo Schiff\u201d, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6788-4731","authenticated-orcid":false,"given":"Craig","family":"Grimmer","sequence":"additional","affiliation":[{"name":"School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg 3200, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-7028-0629","authenticated-orcid":false,"given":"Igor Vasyl","family":"Nikolayenko","sequence":"additional","affiliation":[{"name":"School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg 3200, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"83","DOI":"10.2174\/1877944105666150417231938","article-title":"Peculiar sequence of the thermodynamic protonation parameters for bis-chelate ligands with methylhydroxyiminoethanamide moieties","volume":"5","author":"Nikolayenko","year":"2015","journal-title":"Curr. Inorg. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8208","DOI":"10.1021\/bi992992v","article-title":"Recognition of \u03b1-amino acids bearing various C=NOH functions by nitric oxide synthase and arginase involves very different structural determinants","volume":"39","author":"Moali","year":"2000","journal-title":"Biochemistry"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.abb.2007.04.036","article-title":"Expression, purification, assay, and crystal structure of perdeuterated human arginase I","volume":"465","author":"Moulin","year":"2007","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"478","DOI":"10.1016\/j.ica.2012.03.042","article-title":"Novel tetranuclear distorted open-cubane copper complex containing oximate bridges: Synthesis, crystal structure, DNA binding and cleavage activity","volume":"392","author":"Pagonda","year":"2012","journal-title":"Inorg. Chim. Acta"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"11744","DOI":"10.1021\/ic401020m","article-title":"Di-, tri-, and tetranuclear nickel(II) complexes with oximato bridges: Magnetism and catecholase-like activity of two tetranuclear complexes possessing rhombic topology","volume":"52","author":"Das","year":"2013","journal-title":"Inorg. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"918","DOI":"10.1071\/CH12100","article-title":"Linear trinuclear copper(II) complexes derived from the nucleophilic addition products of dicyanonitrosomethanide [C(CN)2(NO)]\u2013: Syntheses, structures, and magnetic properties","volume":"65","author":"Razali","year":"2012","journal-title":"Aust. J. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1857","DOI":"10.1021\/ja00474a033","article-title":"Polyfunctional catalysis of acetyl phosphate decomposition","volume":"100","author":"Lau","year":"1978","journal-title":"J. Am. Chem. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3629","DOI":"10.1039\/a804763d","article-title":"Co-ordination ability of novel tetradentate amide-and-oxime ligands: Differential binding to CuII and NiII","volume":"21","author":"Fritsky","year":"1998","journal-title":"J. Chem. Soc. Dalton. Trans."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3853","DOI":"10.1039\/a703202a","article-title":"Co-ordination of copper(II) and nickel(II) ions by a novel open chain oxime ligand","volume":"20","author":"Duda","year":"1997","journal-title":"Dalton. Trans."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1432","DOI":"10.1039\/B316698H","article-title":"In vitro and in vivo stability investigations of Cu(II), Zn(II), Ca(II) and Gd(III) complexes with N,N\u2019-bis(2-hydroxyiminopropionyl) propane-1,3-diamine","volume":"9","author":"Nomkoko","year":"2004","journal-title":"Dalton. Trans."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1515\/znb-1999-0406","article-title":"Crystal and molecular structure of two tetradentate \u201coxime-and-amide\u201d ligands","volume":"54b","author":"Fritsky","year":"1999","journal-title":"Z. Naturforsch."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1535","DOI":"10.1039\/a801781f","article-title":"A short intramolecular hydrogen bond is a key factor in the self-assembly of a dimeric complex with a 22-membered metallamacrocyclic cavity","volume":"10","author":"Fritsky","year":"1998","journal-title":"J. Chem. Soc. Dalton Trans."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3746","DOI":"10.1016\/j.ica.2004.04.025","article-title":"Hydrogen bonded supramolecular structures of cationic and anionic module assemblies containing square-planar oximate complex anions","volume":"357","author":"Fritsky","year":"2004","journal-title":"Inorg. Chim. Acta"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1428","DOI":"10.1039\/B418598F","article-title":"Effect of metal ionic radius and chelate ring alternation motif on stabilization of trivalent nickel and copper in binuclear complexes with double cis-oximato bridges","volume":"8","author":"Kanderal","year":"2005","journal-title":"Dalton. Trans."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"966","DOI":"10.1515\/znb-2000-1013","article-title":"Preparation and crystal structure of a mixed metal assembly [Ni(phen)3][Cu(H-1pap)]2(NO3) \u00b7 8 H2O featuring octahedral cationic and square-planar anionic modules","volume":"55b","author":"Fritsky","year":"2000","journal-title":"Z. Naturforsch"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4125","DOI":"10.1039\/B608236J","article-title":"Efficient stabilization of copper(III) in tetraaza pseudo-macrocyclic oxime-and-hydrazide ligands with adjustable cavity size","volume":"39","author":"Fritsky","year":"2006","journal-title":"Chem. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6266","DOI":"10.1039\/c0dt00008f","article-title":"Dimeric versus polymeric coordination in copper(II) cationic complexes with bis(chelating) oxime and amide ligands","volume":"39","author":"Buvailo","year":"2010","journal-title":"Dalton Trans."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"m1139","DOI":"10.1107\/S1600536809033467","article-title":"Poly[bis [\u03bc4-N-(2-hydroxyiminopropionyl)-N\u2019-(2-oxidoimino propionyl)propane-1,3-diaminato]dimethano lcalciumdicopper(II)]","volume":"65","author":"Kalibabchuk","year":"2009","journal-title":"Acta Crystallogr. Sect. E Struct. Rep. Online"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1107\/S0567739476001551","article-title":"Revised effective ionic radii and systematic studies of interatomie distances in halides and chaleogenides","volume":"A32","author":"Shannon","year":"1976","journal-title":"Acta Crystallogr."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4767","DOI":"10.1021\/ja01551a004","article-title":"Intermolecular Metal-Metal Bonds and Absorption Spectra of Some Nickel(II) and Palladium(II) Complexes of vic-Dioximes1","volume":"80","author":"Banks","year":"1958","journal-title":"J. Am. Chem. Soc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"755","DOI":"10.1021\/ja01512a066","article-title":"Crystal structures of nickel and palladium dimethylglyoximes","volume":"81","author":"Williams","year":"1959","journal-title":"J. Am. Chem. Soc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/S0003-2670(01)85496-9","article-title":"The solution chemistry of ethylmethylglyoxime","volume":"48","author":"Egneus","year":"1969","journal-title":"Anal. Chim. Acta"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"m1094","DOI":"10.1107\/S1600536803024656","article-title":"Redetermination of bis(dimethylglyoximato-\u03ba2N,N\u2032)nickel(II)","volume":"59","author":"Li","year":"2003","journal-title":"Acta Crystallogr. Sect. E Struct. Rep. Online"},{"key":"ref_24","unstructured":"Czapik, A., and Gdaniec, M. (2009). CSD Communication, University of Cambridge."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"24705","DOI":"10.1021\/jp508939g","article-title":"Structural properties of nickel dimethylglyoxime at high pressure: Single-crystal X-ray diffraction and dft studies","volume":"118","author":"Zakharov","year":"2014","journal-title":"J. Phys. Chem. C"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"5507","DOI":"10.1021\/ja00997a068","article-title":"Complexes of bromine and iodine with bis-(diphenylglyoximato)nickel(II) and bis(diphenylglyoximato)palladium(II)","volume":"89","author":"Foust","year":"1967","journal-title":"J. Am. Chem. Soc."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3545","DOI":"10.1021\/ja00845a058","article-title":"Solid state structure and oxidation states in bis(diphenylglyoximato)nickel and -palladium iodides","volume":"97","author":"Gleizes","year":"1975","journal-title":"J. Am. Chem. Soc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2921","DOI":"10.1021\/ja00505a021","article-title":"Rational synthesis of unidimensional mixed valence solids. Structural, spectral, and electrical studies of charge distribution and transport in partially oxidized nickel and palladium bisdiphenylglyoximates","volume":"101","author":"Cowie","year":"1979","journal-title":"J. Am. Chem. Soc."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1077","DOI":"10.1021\/ic00149a014","article-title":"Bis[3-(hydroxyamino)-3-methyl-2-butanone oximato(2-)-N,N\u2019]nickel. Structure and properties of a [Ni(DMG)2]0-related complex","volume":"22","author":"Schlemper","year":"1983","journal-title":"Inorg. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6168","DOI":"10.1021\/acs.cgd.2c00717","article-title":"Nickel(II) aqua complexes with chelating ligands: What happens when water is gone?","volume":"22","author":"Opalade","year":"2022","journal-title":"Cryst. Growth Des."},{"key":"ref_31","unstructured":"CrysAlis RED and Scakle3 Abspack, Version 1.171.32.29."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1107\/S0021889898007717","article-title":"SIR97: A new tool for crystal structure determination and refinement","volume":"32","author":"Altomare","year":"1999","journal-title":"J. Appl. Crystallogr."},{"key":"ref_33","first-page":"50","article-title":"Aspherical scattering factors for SHELXL\u2014Model, implementation and application","volume":"A75","author":"Wandtke","year":"2019","journal-title":"Acta Crystallogr. A Found. Adv."},{"key":"ref_34","unstructured":"(2023, March 01). Mercury 2023.1.0 (Build 376230). Copyright \u00a9 CCDC, 2001\u20132023. Available online: https:\/\/www.ccdc.cam.ac.uk\/solutions\/software\/mercury\/."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1107\/S1600576719014092","article-title":"Mercury 4.0: From visualization to analysis, design and prediction","volume":"53","author":"Macrae","year":"2020","journal-title":"J. Appl. Crystallogr."},{"key":"ref_36","unstructured":"(2023, March 01). EnCIFer 2023.1.0 (Build 376230). Copyright \u00a9 CCDC. 2001\u20132023. Available online: https:\/\/www.ccdc.cam.ac.uk\/solutions\/software\/encifer\/."},{"key":"ref_37","unstructured":"(2023, March 01). Olex2 v1.5 Copyright \u00a9 OlexSys Ltd. 2004\u20132023. Available online: https:\/\/www.olexsys.org\/olex2\/."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1107\/S0021889897003117","article-title":"ORTEP-3 for windows\u2014A version of ORTEP-III with a graphical user interface (GUI)","volume":"30","author":"Farrugia","year":"1997","journal-title":"J. Appl. Cryst."},{"key":"ref_39","first-page":"171","article-title":"The Cambridge Structural Database","volume":"B72","author":"Groom","year":"2016","journal-title":"Acta Crystallogr."},{"key":"ref_40","unstructured":"Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman, J.R., Scalmani, G., Barone, V., Petersson, G.A., and Nakatsuji, H. (2016). Gaussian 09, Revision 9.0, Gaussian, Inc."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2999","DOI":"10.1021\/cr9904009","article-title":"Quantum mechanical continuum solvation models","volume":"105","author":"Tomasi","year":"2005","journal-title":"Chem. Rev."},{"key":"ref_42","unstructured":"Glendening, E.D., Reed, A.E., Carpenter, J.E., and Weinhold, F. (2023, March 01). NBO Version 3.1; 2001, Pittsburg. Available online: http:\/\/www.ccl.net\/cca\/software\/MS-WIN95-NT\/mopac6\/nbo.htm."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1039\/C2CS35394F","article-title":"The calculations of excited-state properties with Time-Dependent Density Functional Theory","volume":"42","author":"Adamo","year":"2013","journal-title":"Chem. Soc. Rev."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/29\/2\/522\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T13:46:28Z","timestamp":1760103988000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/29\/2\/522"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,1,20]]},"references-count":43,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2024,1]]}},"alternative-id":["molecules29020522"],"URL":"https:\/\/doi.org\/10.3390\/molecules29020522","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,1,20]]}}}