The reactions of 18-crown-6 with [k(18-C-6)]~2[M(NO~2)~4] (H~2O) (M=Pd,Pt) were studied and the complex k(18-C-6)]~2 [Pd(no~2)~4](H~2o) ~0.5(1) and complex [k(18-C-6)]~2,k~2[Pt(NO~2)~4]) (H~2O)(2)were characterized by X -ray diffraction analysis. Two complexes belong to monoclinic, group P2~1/c with cell dimensions, 1α=1,7104(3),c=1,5763 (3)nm ,β=93.49(3)°, V=3.9987(14)nm^3, Z =4, D~c=1.507g/cm^3, F(000) =1880,R~1=0.0681, ~wR~2=0.1004 and 2: a=1.1312(3)nm, b=1.4227(2)nm, c=1.2266(3)nm, β93.141(10)°,V= 1.9711(8)nm^3, Z=4, D~c=1.614g/cm^3, F(000)=936, R~1=0.0265, ~w R~2=0.0721.In the solid state, complex 1 contains two molecules :[(18-c-6)]~2[Pd(NO~2)~4](H~2O)(1a) and[(18-c- 6)]~2[Pd·(NO~2)~4] (1b).The former has a one --dimensional chain containing two [k(18- C-6)]^+complex cations a [Pd(NO~2)~4]^2- anion hridged by one H~2O molecule between the adjacent [k(18-C-6)]^+ units. Complex 2 also has a one -dimensional chain consisting of two [k(18-C-6)]^+ complex cations and a[Pd(NO~2)~4]^2 anion bridged by one H~2O molecule between the adjacent [k(18-C-6)]^+untis.

Key words: CROWN ETHER, CRYSTAL GROWTH, ELEMENTAL ANALYSIS, INFRARED SPECTROPHOTOMETRY, X-RAY DIFFRACTION ANALYSIS, PALLADIUM COMPLEX, PLATINUM COMPLEX