Naslov
Polyoxomolybdates co-ordinated by glycyl-glycine: Structures of Na_4[Mo_8O_2_6(glygly)_2] . 15H_2O (I) and Na_4[Mo_8O_2_6(glygly)_2] . 12H_2O (II)

Autori
Kajfež , Tanja ; Cindrić, Marina ; Strukan, Neven ; Kamenar, Boris ;

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstracts / Golič, Ljubo; - Ljubljana : Univerza v Ljubljani, 2002, 32-32

Skup
11th Slovenian-Croatian Crystallographic meeting

Mjesto i datum
Bohinj, Slovenija, 27.07.2002. - 30.07.2002

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
glycyl-glycine; polyoxomolybdates; antiviral activities

Sažetak
It has been observed that polyoxomolybdates exhibit antitumor activity.1 Therefore, structural chemistry of polyoxomolybdates with organic ligands is essential for understanding their antitumor or antiviral activities. Here we describe the crystal structures of two gama-type octamolybdates coordinated with glycyl-glicine. Crystal data: (I) Na_4[Mo_8O_2_6(glygly)_2] . 15H2O, Mr = 1801.9, triclinic, a = 10.945(5), b = 11.530(4), c = 11.870(5) Å, alfa = 64.70(3)A beta = 64.26(3)A gama = 82.83(3)A, V = 1231.6(9) Å^3, Z = 2, space group , Dcalc = 2.465 g cm^-^3, F(000) = 870, *(MoK*) = 0.7107 Å . (II) Na_4[Mo_8O_2_6(glygly)_2] . 12H_2O, Mr = 1753.9 , triclinic , a = 9.4207(8), b = 11.3205(8), c = 11.8201(11) Å, alfa = 63.896(6)A beta = 74.109(7)A gama = 82.371(7)A, V = 1088.63(16) Å^3, Z = 2, space group , Dcalc = 2.675 g cm^-^3, F(000) = 846, *(MoK*) = 0.7107 Å . Both crystal structures consist of centrosymmetric -octamolybdate [Mo_8O_2_6]^4^- anions, sodium cations and water molecules. The anions in (I) and (II) are built up of eight edge sharing MoO6 octahedra with the usual distribution of metal-to-oxygen bond lenghts: two short Mo-O bonds [from 1.704(2) to 1.751(2) Å], two bonds of intermediate lenght [from 1.876(2) to 1.967(2) Å] and two long bonds [from 2.135(2) to 2.453(2) Å]. Dipeptide glycyl-glycine is coordinated via monodentate carboxylate-oxygen atom occupying the vacant sites of two five coordinated molybdenum atoms in the centrosymmetric beta-[Mo_8O_2_6]^4^- anions. It has been observed that glycyl-glycine molecules have different conformations. The water molecules are hydrogen bonded to the terminal and bridging oxygen atoms. Sodium cations are octahedrally coordinated by oxygen atoms from the anion and water molecules thus forming edge sharing octahedra.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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