Unique Copper–Organic Networks Self-Assembled from 1,3,5-Triaza-7-Phosphaadamantane and Its Oxide: Synthesis, Structural Features, and Magnetic and Catalytic Properties

Abstract

Three new coordination compounds, namely, a zero-dimensonal dicopper­(II) complex [Cu2(μ-MeCOO)4­(MeOH)2]­(PTA = O)2 (1), a three-dimensional (3D) copper­(II)-organic framework [Cu3(μ-MeCOO)6­(μ3-PTAO)] n ­·3.5nMeCN (2), and a mixed-valence copper­(I/II) one-dimensional (1D) coordination polymer [Cu3(μ-MeCOO)4­(MeCOO)­(μ-PTA)2­(PTA)] n (3), were self-assembled from copper­(II) acetate and cage-like aminophosphine 1,3,5-triaza-7-phosphaadamantane (PTA) or its P-oxide (PTAO). The obtained products were isolated as air-stable crystalline solids and characterized by IR and electron paramagnetic resonance spectroscopy, thermogravimetric and elemental analysis, as well as single crystal X-ray diffraction. Although all compounds bear dicopper­(II) paddle-wheel tetraacetate [Cu2(μ-MeCOO)4] blocks, they are arranged into very distinct metal–organic architectures. The structure of 2 reveals an intricate 3D metal–organic framework (MOF) driven by the μ3-PTAO spacers acting in an unusual N,N,O-tridentate mode, whereas the compound 3 discloses an infinite 1D wave-like metal–organic chain with the dicopper­(II) [Cu2(μ-MeCOO)4] and monocopper­(I) [Cu­(PTA)­(MeCOO)] blocks being interlinked by the μ-PTA linkers acting in an N,P-bidentate mode. Topological analysis of underlying nets was performed, revealing a decorated uninodal 3-connected framework with the ths topology in 2 and a uninodal 2-connected chain with the 2C1 topology in 3. Compounds 2 and 3 broaden a still very limited family of MOFs or coordination polymers assembled from PTA or its P-oxide building blocks, also showing that PTA can be applied for the generation of unusual mixed-valence copper­(I/II) derivatives. Besides, 2 represents the first example of a copper-containing 3D MOF that is driven by PTAO or any other PTA-derived block. Magnetic properties of 1–3 were investigated, modeled, and discussed in detail, resulting in the exchange coupling parameters (J = −310, −320 cm–1) that indicate a strong antiferromagnetic interaction within the dicopper­(II) paddle-wheel blocks. Moreover, compounds 1 and 2 show a notable catecholase activity in the aerobic oxidation of 3,5-di-tert-butyl-catechol to 3,5-di-tert-butyl-o-benzoquinone; turnover frequency values of up to 81 min–1 were attained.

Synthesis, Structural, and Cytotoxic Properties of New Water-Soluble Copper(II) Complexes Based on 2,9-Dimethyl-1,10-Phenanthroline and Their One Derivative Containing 1,3,5-Triaza-7-Phosphaadamantane-7-Oxide

“…α − helix (%) = − MRE 209 − 4000 33000 − 4000 × 100 (10) where MRE is the mean residue ellipticity, C p is the molar concentration of the protein, n the number of amino acid residues (679), and l is the path length (0.1 cm).…”

“…Coordination chemistry of copper compounds has been an important subject of intensive investigations by researchers for many years [1][2][3]. Coordination polymers or discrete complexes constructed of copper metal ions and organic ligands/linkers have been investigated for the design of a new generation for luminescent [4][5][6][7], magnetic [8], catalytic [9][10][11][12], host-guests [13], and biological [14][15][16][17][18][19] properties. Thus, recently, there is great attention on the coordination chemistry of copper(I/II) complexes, due to their structural and physicochemical properties, in particular biological.…”

“…In the last decades the coordination chemistry of PTA and PTA=O has seen a pronounced development justified by the search for water-soluble and stable transition metal complexes [21][22][23]. Currently, several examples of PTA=O coordination modes are known, where a tetrapodal ligand is connected to a metal center in the O- [24][25][26], N- [24,27,28], ON- [24,25], ONN- [10,29], NNN- [30], or ONNNmodes [29,31], achieving either discrete metallic units or polymeric compounds [32]. Among the biorelevant N-donor ligands suitable to afford new bioactive metal complexes, polypyridines represent a good choice due to a recognizable influence on a large variety of biological functions [33][34][35][36][37].…”

“…A series of Cu(I)-dmphen complexes stabilized by tertiary phosphines and other Cu(II)-dmphen coordination compounds have been also reported, but their poor solubility in polar solvents eventually prevented the application of these compounds as bioactive materials [38,39]. In particular, some of us have reported a number of water-soluble copper(I/II)-PTA-cage coordination networks [10,[40][41][42][43][44] as well as a discrete complexes [32,[40][41][42][43][45][46][47][48], which were evaluated successfully for their magnetic [10,43,45], catalytic [10,44], and luminescent properties [40,42,44,48].…”

Stepwise Assembly of an Electroactive Framework from a Co6S8 Superatomic Metalloligand and Cuprous Iodide Building Units

“…The six rigid PTA‐ligands provide 18 Lewis‐basic nitrogen atoms around the exterior of the cluster that can participate in further coordination. In fact, PTA ligands have served as bridging linkers in the assembly of several coordination networks, including materials containing cross‐linked copper iodide clusters . Organophosphine ligands and transition metal phosphine complexes have also emerged as novel linkers for preparing coordination polymers and MOFs .…”