KRISTALNA STRUKTURA NOVOG HETERONUKLEARNOG POLIMERA [Cu2Mn(C8H4O4)3(C10H9N3)2]n

Abstract

U proteklih nekoliko godina intenzivno se ispituje ideja o heterometalnim koordinacionim jedinjenjima, zbog mogućnosti da se uvođenjem različitih prelaznih metala poboljšaju katalitička, magnetna, fotoluminiscentna i druga svojstva materijala [1]. Kao doprinos tome, predstavljamo sintezu i kristalnu strukturu heteronuklearnog kompleksa sa jonima Cu2+ i Mn2+, anjonom 1,4-benzendikarboksilne kiseline (tereftalne kiseline, H2tpht) i 2,2’-dipiridilaminom (dipya) kao terminalnim ligandom. Polimerni kompleks [Cu2Mn(dipya)2(tpht)3]n dobijen je hidrotermalnom metodom u čeličnom autoklavu sa teflonskom oblogom (zagrevanje na 160 °C tokom 4 dana i hlađenje do sobne temperature tokom 8 h). Multidentatni načini koordinacije tpht liganada, prikazani na shemi, veoma su složeni: tpht1 je koordiniran kao bis-helat i bis-monomost, dok je tpht2 kombinovani, bidentatni i monomostovni ligand, a oba liganda zajedno učestvuju u formiranju polimernih slojeva paralelnih sa bc-ravni. Geometrija oko oba atoma, i Mn2+ i Cu2+, može se opisati kao oktaedarska, s tim da je oktaedar oko Cu2+ značajno deformisan. Slojevi su stabilizovani nekovalentnim C–H∙∙∙π interakcijama (H∙∙∙Cg rastojanje iznosi 2,834 Å) između H-atoma sa prstena jednog dipya liganada i susednog aromatičnog prstena u sloju. Intermolekulskim vodoničnim vezama, uspostavljenim između aminskog H-atoma i nekoordiniranog O-atoma koji pripada tpht2, slojevi su povezani u 3D strukturu. Osnovni kristalografski podaci kompleksa jesu: C44H30Cu2MnN6O12, Mr = 1016,78, rombični sistem, prostorna grupa Pbca, a = 10,901(2), b = 16,032(3), c = 23,843(5) Å, V = 4167(1) Å 3 , Z = 4, F(000) = 2060, x = 1,621 g cm–3 ,  (Mo K) = 1,384 mm–1 . Utačnjavanje sa F 2 (303 parametra) dalo je R1 = 0,0305, wR2 = 0,0702, S = 1,048 za sve podatke, i R1 = 0,0269 za 3729 refleksija sa I  2σ(I).

In the past several years, the concept of heterometallic coordination compounds has been increasingly investigated due to opportunity to incorporate different transition metal centers in supramolecular materials to enhance their catalytic, magnetic, photoluminescent and other properties [1]. In this contribution, we present the synthesis and crystal structure of a heteronuclear complex containing Cu2+ and Mn2+ ions with anion of 1,4-benzenedicarboxylic acid (terephthalic acid, H2tpht) and terminal 2,2’-dipyridylamine (dipya) ligand. The polymeric [Cu2Mn(dipya)2(tpht)3]n complex has been prepared by the hydrothermal method in a Teflon-lined steel autoclave (at 160 °C for 4 days and cooled to room temperature for 8 h). The multidentate coordination modes of tphts, presented in Scheme, are very complex: tpht1 is coordinated as bis-chelate and bis-monobridge, while tpht2 is combined, bidentate and monobridge ligand, making together polymeric layers parallel to the bc-plane. The geometry around both Mn2+ and Cu2+ can be described as octahedral, wherein the Cu2+ octahedron is highly deformed. The layers are stacked by non-covalent C–H∙∙∙π interactions (H∙∙∙Cg distance is 2.834 Å) formed between H atom from one pyridyl ring of dipya and adjacent ring in the layer. By intermolecular hydrogen bonds between amine H atom from dipya and non-coordinated O atom from tpht2, the layers are connected into the 3D structure. The main crystallographic data for the titled complex are: C44H30Cu2MnN6O12, Mr = 1016.78, orthorhombic, space group Pbca, a = 10.901(2), b = 16.032(3), c = 23.843(5) Å, V = 4167(1) Å 3 , Z = 4, F(000) = 2060, x = 1.621 g cm–3 ,  (Mo K) = 1.384 mm–1 . The refinement on F 2 (303 parameters) yielded R1 = 0.0305, wR2 = 0.0702, S = 1.048 for all data, and R1 = 0.0269 for 3729 observed reflections with I  2σ(I).