Coordination compounds with biological active ions and molecules are of great interest in biotechnology and biomedicine. Coordination compounds such as iron containing enzymes, siderophores, and others are known for their essential role in life processes as oxygen carriers [1]. The importance of alkali metals in biological systems is well-known. Coordination chemistry of lithium, sodium and potassium has colossal value due to their remarkable role in different biological mechanisms, especially for cell biology and natural fluids biochemistry. For example, Na+ and K+ are responsible for maintenance of the ionic equilibrium in living bodies and for electrochemical gradients across cell membranes which affect transmission of nerve impulse and regulation of cell functions [2]. Herein, we report a new coordination cluster with composition [Fe4Na2O2(piv)10(MeCN)2] (1) synthetized by refluxing the mixture of hexanuclear iron (III) pivalate, [Fe6O2(OH)2(piv)12] (Hpiv = pivalic acid) and sodium azide NaN3 in MeCN. X-ray structural analysis revealed that compound 1 crystalizes in monoclinic Cc space group with following unit cell parameters: a = 19.3924(9), b = 19.1240(15), c = 20.0436(12) Å, β = 91.136(4)º. The cluster core {Fe4Na2} contains two Fe-Fe edge sharing distorted Fe3Na tetrahedra with μ4-O2 bridges inside each tetrahedron. Coordination spheres of Na+ ions consist of four O atoms from three pivalate ligands, one μ4-O2 moiety and one N atom from capped acetonitrile molecule, resulting in NO4 distorted trigonal-bipyramidal surrounding. Peripheral ligation of Fe and Na atoms is provided by six bridging in η1:η1:μ2 mode and four bridging in η1:η2:μ3 pivalate ligands. The bond distances Na O are in the range 2.255(14) – 2.486(10) Å, Na N equal 2.415 (16) and 2.549(16) Å, Fe O bond distances fit the interval of 1.847(8) – 2.196(9) Å. All iron atoms are hexacoordinated, displaying O6 distorted octahedra. The BVS calculations and charge balance prove the Fe(III) oxidation state of all iron atoms in the cluster.