**4.1 Spectroscopic and magnetic properties of a gadolinium macrobicyclic complex**

Because of Schiff base buildup, gadolinium cryptate has been blended and researched by infrared (IR) spectroscopy and electron paramagnetic reverberation (EPR) method. Correlation of IR groups in a ligand and the gadolinium complex affirmed the arrangement of the gadolinium cryptate complex. IR and thermogravimetry-differential warm examination (TG-DTA) investigations demonstrate the nearness of two water particles in the inward circle of the complex. Mass spectroscopy examinations affirmed a monometallic substitution of the Gd3+ particle into the macrobicycle ligand. EPR spectra of the complex have been enrolled in the 3–300 K temperature go. Every range has been recreated utilizing the EPR–NMR PC program and the estimations of the turn Hamiltonian parameters at every temperature have been determined. The warm reliance of the turn Hamiltonian parameters has been explored. The temperature reliance of the incorporated force of the EPR range uncovered the attractive connections in the turn arrangement of this compound. No long-extend attractive request has been identified in the 3–300 K go, however a solid antiferromagnetic association in the high-temperature run, over 160 K, has been watched [26].
