Novel benzo-18-crown-6 (B18C6)_6]} [Pt(SCN)_6](SCN)_2 (1) and [K (B18C6)]_2[Pt(SCN)_6]·H—2O (2) were synthesized and characterized by elemental analysis, IR spectra and X-ray diffraction analysis. 1 belongs to rhomobohedral, space group R3 with cell dimensions: a=b=1. 9933(3)nm, c=2.9760(6)nm,α=β=90°,γ=120°, ν_calcd=1.476g/cm~3, F (000)=666, R_1=0.0696, w_R_2=0.1346.1 is composed of one {[Na (B18C6)] units. The function of [Pt(SCN)_6]~(2-) complex anion and two SCN~- anions. {[Na(B18C6)]_6 [Pt(SCN)_6]}(4+) complex cations show a three- dimensional network structure bridged by Na-O interactions between the adjacent [Na(B18C6)units. The function of [Pt(SCN)_6]~(2-) complex anion and two SCN~- anions are balancing the charge in the crystal. 2 is made up of two [Na(B18C6)]~+ complex cations and one [Pt(SCN)_6]~(2- ) complex anion. They form one-dimensional chain structure bridged by K- O interactions between the adjacent [K(B18C6)~+ units.

Key words: SOLID COMPLEX, BENZO-, SYNTHESIS, STRUCTURE, SODIUM, POTASSIUM, PLATINUM, ALKALI METAL, X-RAY DIFFRACTION ANALYSIS, INFRARED SPECTROSCOPY