10.1021/ic970593n.s001 Konstantinos Chondroudis Konstantinos Chondroudis Mercouri G. Kanatzidis Mercouri G. Kanatzidis Julien Sayettat Julien Sayettat Stéphane Jobic Stéphane Jobic Raymond Brec Raymond Brec Palladium Chemistry in Molten Alkali Metal Polychalcophosphate Fluxes. Synthesis and Characterization of K<sub>4</sub>Pd(PS<sub>4</sub>)<sub>2</sub>, Cs<sub>4</sub>Pd(PSe<sub>4</sub>)<sub>2</sub>, Cs<sub>10</sub>Pd(PSe<sub>4</sub>)<sub>4</sub>, KPdPS<sub>4</sub>, K<sub>2</sub>PdP<sub>2</sub>S<sub>6</sub>, and Cs<sub>2</sub>PdP<sub>2</sub>Se<sub>6</sub> American Chemical Society 1997 Cs 2 PdP 2 Se 6 n 2 n orthorombic space group Pnma K 2 PdP 2 S 6 PdP 2 Q 6 P 2 Q 6 crystallize KPdPS 4 DTA Molten Alkali Metal Polychalcophosphate Fluxes UV 4. III VI IV II 1997-12-03 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Palladium_Chemistry_in_Molten_Alkali_Metal_Polychalcophosphate_Fluxes_Synthesis_and_Characterization_of_K_sub_4_sub_Pd_PS_sub_4_sub_sub_2_sub_Cs_sub_4_sub_Pd_PSe_sub_4_sub_sub_2_sub_Cs_sub_10_sub_Pd_PSe_sub_4_sub_sub_4_sub_KPdPS_sub_4_sub_K_sub_2_sub_PdP_/3619305 The reaction of Pd with a molten mixture of A<sub>2</sub>Q<i><sub>x</sub></i>/P<sub>2</sub>Q<sub>5</sub>/Q (A = K, Q = S, <i>x</i> = 3; A = Cs, Q = Se, <i>x</i> = 1) produced the molecular compounds K<sub>4</sub>Pd(PS<sub>4</sub>)<sub>2</sub> (<b>I</b>), Cs<sub>4</sub>Pd(PSe<sub>4</sub>)<sub>2</sub> <b>(II)</b>, and Cs<sub>10</sub>Pd(PSe<sub>4</sub>)<sub>4</sub> <b>(III)</b> and the solid-state KPdPS<sub>4</sub> (<b>IV</b>), K<sub>2</sub>PdP<sub>2</sub>S<sub>6</sub> <b>(V)</b>, and Cs<sub>2</sub>PdP<sub>2</sub>Se<sub>6</sub> <b>(VI)</b>. Compounds <b>I</b>−<b>III</b> are air and water sensitive, while <b>IV</b>−<b>VI</b> are air and water stable. All crystals are red or dark red except those of <b>VI</b>, which are black. All of them exhibit a rodlike shape. Compound <b>I</b> crystallizes in the triclinic space group <i>P</i>1̄ (No. 2) with <i>a</i> = 6.380(1) Å, <i>b</i> = 6.897(1) Å, <i>c</i> = 8.999(1) Å, α = 87.777(8)°, β = 81.581(8)°, γ = 84.429(9)°, and <i>Z</i> = 1. Compound <b>II</b> crystallizes in the monoclinic space group <i>P</i>2<sub>1</sub>/<i>c</i> (No. 14) with <i>a</i> = 7.491(2) Å, <i>b</i> = 13.340(2) Å, <i>c</i> = 10.030(3) Å, β = 92.21(2)°, and <i>Z</i> = 2. Compound <b>III</b> crystallizes in the tetragonal space group <i>P</i>4̄2<i>c</i> (No. 112) with <i>a</i> = <i>b</i> = 13.949(2) Å, <i>c</i> = 11.527(2) Å, and <i>Z</i> = 4. Compound <b>IV</b> crystallizes in the tetragonal space group <i>P</i>4<sub>2</sub>/<i>mnm</i> (No. 136) with <i>a</i> = <i>b</i> = 8.5337(2) Å, <i>c</i> = 10.5595(5) Å, and <i>Z</i> = 4. Compound <b>V</b> crystallizes in the orthorombic space group <i>Pnma</i> (No. 62) with <i>a</i> = 15.612(2) Å, <i>b</i> = 7.0724(7) Å, <i>c</i> = 10.080(1) Å, and <i>Z</i> = 4. Compound <b>VI</b> crystallizes in the monoclinic space group <i>C</i>2/<i>c</i> (No. 15) with <i>a</i> = 12.9750(4) Å, <i>b</i> = 8.3282(2) Å, <i>c</i> = 13.0568(1) Å, β = 102.940(2)°, and <i>Z</i> = 4. Compounds <b>I</b>−<b>III</b> contain the discrete complexes [Pd(PQ<sub>4</sub>)<sub>2</sub>]<sup>4-</sup> (Q = S, Se). The mixed salt <b>III</b> contains additional noncoordinating [PSe<sub>4</sub>]<sup>3-</sup> units. The structure of <b>IV</b> consists of Pd(II) in square planar sulfur coordination linked by edge-sharing [PS<sub>4</sub>]<sup>3-</sup> tetrahedral groups to produce one-dimensional chains. The structures of <b>V</b> and<b> VI</b> feature the [P<sub>2</sub>Q<sub>6</sub>]<sup>4-</sup> (Q = S, Se) group coordinated to the square planar Pd<sup>2+</sup> atoms, yielding [PdP<sub>2</sub>Q<sub>6</sub>]<i><sub>n</sub></i><sup>2</sup><i><sup>n</sup></i><sup>-</sup> chains. Physical characterization was performed with DTA, far-IR spectroscopy, solid-state UV/vis diffuse reflectance spectroscopy, and single-crystal optical transmission.