A synthetic, spectroscopic, and theoretical study of Ex(CN)2 (E = S, Se; x = 1-3) is described. The X-ray structures of Se2(CN)2 and Se3(CN)2 have been determined. Se2(CN)2 crystallizes in a chiral space group with the CN groups approximately gauche.

The synthesis and full characterisation of a series of 1,2,4-thiadiazoles is reported. (SCN)(x) has been studied by a variety of techniques and the data compared with 1,2,4-thiadiazole and 1,2,4-dithiazoles. The observed data suggest that the polymer consists of 1,2,4-dithiazole rings linked by nitrogen atoms. For (SCN)(x), the MALDI-TOF mass spectroscopy showed a parent ion at 1149 and a series of peaks with (SCN)(2) repeat units (116 m/z); this result implies that (SCN)(2) may be the monomer unit of the polymer. Its IR spectrum shows a very broad peak with maximum at 1134 cm(-1) consisting of several overlapping peaks in the same region as ring vibrations for 1,2,4-thiadiazole and 1,2,4-dithiazole compounds. Peaks in the Raman spectrum in the range 400-480 cm(-1) support the presence of disulfide units within the polymer. The solid-state (13)C NMR (99 % (13)C-labelled) spectrum is dominated by two singlets of equal intensity at approximately 187 and 184 ppm with low intensity peaks in the range 152-172 ppm, in approximately the same range as both 1,2,4-thiadiazoles and 1,2,4-dithiazoles. The solid-state (15)N NMR (99 % (15)N labelled) spectrum displays two major peaks of similar intensity at 236.9 and 197.2 ppm, which are clearly very different environments to those observed in bis(3-bromo-1,2,4-thiadiazol-5-yl) disulfide, but similar to 1,2,4-dithiazoles. The X-ray structures of seven C-S-N systems are reported. Preliminary studies on (SeCN)(x) suggest that literature references to this polymer may be in error with the red solid actually being red selenium.

The title compound is a salt, 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2(11,14)]triaconta-1(26),11(29),12,14(30),24,27-hexaene-3,5-dinitrobenzoic acid-methanol (1/4/2), C24H42N6(4+).4C7H3N2(O6)(-).2CH4O, in which the cation lies across a centre of inversion and one of the two independent anions is positionally disordered over two sets of atom sites having equal occupancy. The components are linked by four types of N-H...O hydrogen bond [N...O 2.674 (2)-2.815 (2) A; N-H.O 149-163 degrees] and one type of O-H...O hydrogen bond in which the acceptor is disordered over two closely adjacent sites [O...O 2.67 (4) and 2.75 (4) A; O-H...O 172 and 173 degrees], forming centrosymmetric seven-component aggregates.

[PPh4]2[M(C2N2S2)2](M = Pt, Pd) and [Pt(C2N2S2)(PR3)2](PR3= PMe2Ph, PPh3) and [Pt(C2N2S2)(PP)](PP = dppe, dppm, dppf) were all obtained by the reaction of the appropriate metal halide containing complex with potassium cyanodithioimidocarbonate. The dimeric cyanodithioimidocarbonate complexes [[Pt(C2N2S2)(PR3)]2](PR3 = PMe2Ph), [M[(C2N2S2)(eta5-C5Me5)]2](M = Rh, Ir)and [[Ru(C2N2S2)(eta6-p-MeC6H4iPr)]2] have been synthesised from the appropriate transition metal dimer starting material. The cyanodithioimidocarbonate ligand is S,S and bidentate in the monomeric complexes with the terminal CN group being approximately coplanar with the CS2 group and trigonal at nitrogen thus reducing the planar symmetry of the ligand. In the dimeric compound one of the sulfur atoms bridges two metal atoms with the core exhibiting a cubane-like geometry.

The 1:1 adduct of piperazine and ethane-1,2-diphosphonic acid is a salt [C(4)H(12)N(2)](2+).[C(2)H(6)O(6)P(2)](2-), in which both ions lie across centres of inversion in space group P2(1)/c. The anions are linked by a single type of O-H...O hydrogen bond [O...O, 2.562 (3) A; H...O, 1.73 A, O-H...O, 169 degrees ] into (6, 3) nets built from a single type of R(4)(4)(22) ring. The cations lie between these nets, linked to them by two types of N-H...O hydrogen bond [N...O, 2.635 (3) and 2.735 (3) A; H...O 1.72 and 1.82 A, N-H...O, 175 and 177 degrees ] such that the cations link adjacent sheets, thus forming a pillared-layer framework. The aquated adduct formed between trimethylenedipiperidine and ethane-1,2-diphosphonic acid is also a salt [C(13)H(28)N(2)](2+).[C(2)H(6)O(6)P(2)](2-).2.8[H(2)O], in which there are 12 different types of hydrogen bond, eight O-H...O and four N-H...O. The anions are linked into chains by pairs of O-H...O hydrogen bonds and these chains are linked by the water molecules into a continuous three-dimensional framework. Within the anion/water framework are large voids which contain pairs of cations, linked to the framework by N-H...O hydrogen bonds.