[Fe（CN）6]^4—还原trans—[Co（en）2（ImH02]^3＋的电子转移反应 …

在不同的温度下，考察了六氰合铁配阴离子「Ｆｅ（ＣＮ）５」＾４－还原ｔｒａｎｓ－「Ｃｏ（ｅｎ）２（ＩｍＨ０２」＾３＋的反应动力学。结果表明，反应遵循Ｈ．Ｔａｕｂｅ所提出的外配位界电子传递机理。在２５℃，Ｉ＝０．５ｍｏｌ．Ｌ＾－１，ｔｒａｎｓ－「Ｃｏ（ｅｎ）２（ＩｍＨ）２」＾３＋／「Ｆｅ（ＣＮ）６」＾４－反应体系的前驱配合物离子对形成常数为Ｑ１ｐ＝９８．９ｍｏｌ＾－１．Ｌ，电子转移速率常数为Ｋｍ＝１．     

稀土脯氨酸配合物[RE_2(L-Pro)_6(H_2O)_4](ClO_4)_6的标准生成焓测定

合成了两种稀土高氯酸盐与Ｌ－脯氨酸配合物的晶体．经热重、差热、化学分析及对比有关文献,知其组成 是［Ｐｒ２（Ｌ－Ｐｒｏ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６和［Ｅｒ２（Ｌ－ＰｒＯ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６,质量分数为９９．２４％和９８．２０％．选用ＲＥ（ＮＯ３）· ６Ｈ２Ｏ（ＲＥ＝Ｐｒ,Ｅｒ）、ＬＰｒｏ、ＮａＣｌＯ４·Ｈ２Ｏ和 ＮａＮＯ３作辅助物,使用具有恒温环境的反应热量计,以 ２ ｍｏｌ·Ｌ－１ＨＣｌ 作溶剂,分别测定了［２ＲＥ（ＮＯ３）３·６Ｈ２Ｏ＋６Ｌ－ＰｒＯ＋６ＮａＣｌＯ４·Ｈ２Ｏ］和｛ ［ＲＥ２（Ｌ－ＰｒＯ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６＋６ＮａＮＯ３｝在 ２９８．１５ Ｋ时的溶解热．设计一热化学循环求得化学反应的反应焓ｒＨ分别是：６３．９０４ ｋＪ·ｍｏｌ－１和 ９１．０１７ ｋＪ·ｍｏｌ－１,经计算得配合物［ＲＥ２（Ｌ－Ｐｒｏ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６（ｓ）在 ２９８．１５ Ｋ时的标准生成焓（２９８．１５ Ｋ）分别 是－６ ５９４．７８ ｋＪ·ｍｏｌ－１和－６ ５３２．８７ ｋＪ·ｍｏｌ－１。     

一经式异构体[Co(N-(3-Aminopropyl)-1,3-propanediamine)(1,2-diamino-2-methylpropane)Cl][ZnCl4]·2H2O的合成及晶体结构

用过氧化物法合成了新体系［ Ｃｏ（ ３, ３－ｔｒｉ）（ ｉｂｎ） ＣＩ］［ ＺｎＣｌ４］（ ３, ３－ｔｒｉ＝ Ｎ－（ ３－Ａｍｉｎｏｐｒｏｐｙｌ）－ １, ３－ｐｒｏｐａｎｅｄｉａ－ｍｉｎｅ; ｉｂｎ＝１, ２－ｄｉａｍｉｎｏ－２－ｍｅｔｈｙｌｐｒｏｐａｎｅ）中的一经式异构体［Ｃｏ（３, ３ｔｒｉ）（ｉｂｎ）ＣＩ］［ＺｎＣｌ４］·２Ｈ２Ｏ,解析了其晶体结构。晶体学参数：三斜晶系,空间群Ｐ１（＃２）,ａ＝９９．５８（２）ｎｍ,ｂ＝１１４．８３（２）ｎｍ,ｃ＝９８．８１（１）ｎｍ,ａ＝９６．７９（２）°,β＝９７．２４３（１０）°,ｙ＝９６．８９（１）°,Ｖ＝１．１０５５（３）Ｘ １０６ｎｍ３,Ｄｅ＝１．６７８ｇ·ｃｍ－３,Ｚ＝２,Ｆ０００＝５７２．００,μ（ Ｍｏ Ｋａ）＝ ２４． ５９ｃｍ－１, Ｒ＝ ０． ０２５, Ｒｗ＝ ０． ０３４。晶胞中含 ２个配位阳离子, ２个 ［ＺｎＣｌ４］２－阴离子及 ４个水分子。     

钴(Ⅲ)—邻菲绕啉混配型配合物的合成及结构研究

在不同条件下合成了［Ｃｏ（ｐｈｅｎ）ｍＸｐ］Ｙ１·ｎＨ２Ｏ型配合物，（ｍ＝１，２；ｐ＝１，２；１＝１－３；ｎ＝０－４；ｐｈｅｎ＝邻菲绕啉；Ｘ＝Ｃｌ－，Ｈ２Ｏ，酒石酸（ｔａｒｔ），甘氨酸（ｇｌｙ），α－皮可林酸（ｐｉｃ）．ＤＬ－两氨酸（ａｌａ），Ｌ－亮氨酸（ｌｅｕ），Ｌ－脯氨酸（ｐｒｏ）；Ｙ＝Ｃｌ－，］并进行了元素分析，热重分析，电子光谱，红外光谱和磁化率测定，计算它们的１０Ｄｑ和Ｂ值．Ｘ－ｒａｙ单晶衍射实验证明：［Ｃｏ（Ｐｈｅｎ）２（Ｈ２Ｏ）２］（ＮＯ３）３·２Ｈ２Ｏ，［Ｃｏ（Ｐｈｅｎ）２（ｇｌｙ）］Ｃｌ２·４Ｈ２Ｏ均为顺式结构．［Ｃｏ（Ｐｈｅｎ）（ａｌａ）２］Ｃｌ·３Ｈ２Ｏ，［Ｃｏ（Ｐｈｅｎ）（ｐｒｏ）２］ＣｌＯ４·４／３Ｈ２Ｏ均为ｔｒａｎｓ（Ｎ）结构．在［Ｃｏ（ｐｈｅｎ）２Ｘ２］（ｎ＋）型配合物中，Ｘ反位的键长均长于顺位键长，其反位效应的顺序为：Ｃｌ－＞羧基，ＮＨ２＞Ｈ２Ｏ。     

[Ce(NO_3)_5H_2O]·(C_3H_5N_2)_2的合成、晶体结构及热分析

稀土盐与咪唑形成的化合物可作为植物生长调节剂,具有一定的促进植物生长,抑制杂菌生长的作用［ｌ,２］,而此类化合物的结构数据尚未见报道。本文以水为溶剂,合成了硝酸铈（Ⅲ）与咪唑形成的无色块状晶体［Ｃｅ（ＮＯ３）５Ｈ２Ｏ］·（Ｃ３Ｈ５Ｎ２）２,测定了晶体结构。用热重法推测了其热分解机理。１实验部分１．ｌ［Ｃｅ（ＮＯ３）５Ｈ２Ｏ］·（Ｃ３Ｈ５Ｎ２）２的合成 将０．２ｍｏｌ的Ｃｅ（ＮＯ３）３·６Ｈ２Ｏ和０．５ｍｏｌ的Ｃ３Ｈ４Ｎ２（咪唑）加入到４０ｍＬ水中,用 １ｍｏｌ·Ｌ－１的 ＨＮＯ３水溶液调节 ｐＨ＝ …     

金属离子与卟啉的嵌入反应动力学研究──Ⅶ．一元酸根催化Cu（Ⅱ）与溴化间－四（N－乙酸甲酯基－3－吡啶基）卟啉的配位反应

研究了在３５±０．１℃、离子强度０．５ｍｏｌ／Ｌ（ＫＣｌ）条件下，甲酸根、乙酸根、丙酸根和丁酸根分别催化Ｃｕ（Ⅱ）离子与四溴化间－四（Ｎ－乙酸甲酯基－３－吡啶基）卟啉（Ｈ２ＴＢ－Ｎ－ＡＣＭＳｐｙＰＢｒ４）的反应动力学及其机理，该类反应对卟啉和Ｃｕ（Ⅱ）离子均为一级反应，反应动力学方程为：ｄ［Ｃｕｐ４＋］／ｄｔ＝ｋ｛（１．０＋ｂ［Ａ－］）／（１．０＋Ｋ３，４·［Ｈ＋］２）｝［Ｃｕ２＋］［ｐ］Ｔ，在甲酸－甲酸根缓冲体系中，ｋ＝２．９８ｍｏｌ－１ｄｍ３·ｓｅｃ－１，ｂ＝１５４×１０２ｍｏｌ－２，ｄｍ６·ｓｅｃ－１，Ｋ３，４＝６．９２８×１０３；在乙酸－乙酸根缓冲体系中，ｋ＝３．４２ｍｏｌ－１·ｄｍ３·ｓｅｃ－１，ｂ＝２．２９×１０３ｍｏｌ－２·ｄｍ６·ｓｅｃ－１，Ｋ３，４＝６．９２８×１０３；在丙酸－丙酸根缓冲体系中，ｋ＝３．００ｍｏｌ－１·ｄｍ３·ｓｅｃ－１，ｂ＝５．９０×１０２ｍｏｌ－２·ｄｍ６·ｓｅｃ－１，Ｋ３，４＝７．００７×１０３；在丁酸－丁酸根缓冲体系中，ｋ＝３．１４ｍｏｌ－１·ｄｍ３·ｓｅｃ－１，ｂ＝３．７５×１０２ｍｏｌ－２·ｄｍ６·ｓｅｃ－１，Ｋ３，４＝６．９２１×１０３；讨论了有机酸根的碱性与     

三维氢键超分子化合物[H3cth][Fe(CN)6]·3H2O的合成与结构

用内消旋５，７，７，１２，１４，１４－六甲基－１，４，８，１１－四氮杂环十四烷（ｃｔｈ）和Ｋ_３［Ｆｅ（ＣＮ）_６〕合成了氢键连接的超分子化合物［Ｈ_３ｃｔｈ］［Ｆｅ（ＣＮ）_３］·３Ｈ_２Ｏ．该化合物的晶体属三斜晶系，Ｐ－１空间群，晶胞参数ａ＝０．９３０ ９７（９）ｎｍ，ｂ＝１．０５１ ６０（１１）ｎｍ，ｃ＝１．６３８ ４７（１７）ｎｍ，ａ＝１０１．０７７（２）°，β＝９０．８６０（２）°，γ＝１１１．６７１（２）°， Ｖ＝１．４５６ ４（３） ｎｍ３， Ｚ＝２， Ｒ＝０．０４１５．晶体中质子化的大环四胺与六氰合铁（Ⅱ ）离子之间通过氢键连接成二维层状结构，而水分子所形成的氢键使化合物呈现三维超分子网络．     

Structural Studies of [V_2S_6O_2(CuPPh_3)_4(CuMeCN)_2]·2CH_2Cl_2·2PrOH

ＳｔｒｕｃｔｕｒａｌＳｔｕｄｉｅｓｏｆ［Ｖ_２Ｓ_６Ｏ_２（ＣｕＰＰｈ_３）_４（ＣｕＭｅＣＮ）_２］·２ＣＨ_２Ｃｌ_２·２ＰｒＯＨＺＨＡＮＧＨａｎ－Ｈｕｉ；ＹＵＸｉｕ－Ｆｅｎ；ＹＡＮＧＲｏｎｇ－Ｓｈｅｎｇ；ＺＨＥＮＧＦａ－Ｋｕｎ；ＨＵＡＮＧＬｉａｏ－Ｙｕ...     

[Ln(EO_2)_3](ClO_4)_3·3H_2O的晶体结构研究

合成了希土高氯酸盐开环冠醚二缩乙二醇（ＥＯ２）晶体，（Ｌｎ＝Ｎｄ，Ｈｏ），测定了结构，文内以Ｎｄ－Ｌ的数据为主要研究对象（方括号内是Ｈｏ－Ｌ的数据）。晶体属单斜晶系，Ｐ２１／ｎ空间群，化学式［Ｌｎ（ＥＯ２）３］（ＣｌＯ４）３·３Ｈ２Ｏ，晶胞参数为：ａ＝１４．１２４（１）［１４．０８７］，ｂ＝１３．９９０（１）［１４．０３９］，ｃ＝１５．２６５（１）［１５．０１４］；β＝９５．７８（１）［９５．６４］°；Ｖ＝３００１．１（６）［２９５５］３；Ｍｒ＝８１５．０１［８３５．７０］；Ｚ＝４；Ｄｃ＝１．８０４［１．８６５］ｇ／ｃｍ３；石墨单色器，μ（ＭｏＫα）＝２．０９［３．０７］ｍｍ－１，最终偏离因子Ｒ＝０．０５５［０．０７４］，ＲＷ＝０．０７１［０．１０９］。研究结果表明晶体具有相同的结构，配位多面体为九配位三帽三棱柱。发现ＥＯ２醚链有绕Ｃ－Ｃ键呈ＳＴＴＳ分布的规律。弱配体高氯酸根不参加配位。     

[C5H4C(CH3)2CH2CH=CH2]Sm(OH)Cl·2MgCl2·4THF的晶体结构分析

用Ｘ－射线晶体结构衍射法测定了［Ｃ５Ｈ４Ｃ（ＣＨ３）２ＣＨ２ＣＨ＝ＣＨ２］Ｓｍ（ＯＨ）Ｃｌ·２ＭｇＣｌ２·４ＴＨＦ的晶体结构。它属三斜晶系,空间群为Ｐ＾－１,ａ＝１０．７７３（２）,ｂ＝１２．８３６（３）,ｃ＝１５．４７８（３）Ａ,ａ＝１１１．４６（３）,β＝１０７．７１（３）,γ＝９２．５４（３）°,Ｖ＝１８６８（１）Ａ＾３,Ｍｒ＝８２７．９１,Ｄｘ＝１．４７２ｇ／ｃｍ＾３,μ＝２．０００６ｍｍ     

Synthese und Kristallstrukturen von [Li(thf)4]2[Bi4I14(thf)2], [Li(thf)4]4[Bi5I19] und (Ph4P)4[Bi6I22]

Synthesis and Crystal Structure of [Li(thf)₄]₂[Bi₄I₁₄(thf)₂], [Li(thf)₄]₄[Bi₅I₁₉], and (Ph₄P)₄[Bi₆I₂₂] Solutions of BiI₃ in THF or methanol react with MI (M = Li, Na) to form polynuclear iodo complexes of bismuth. The syntheses and results of X-ray structure analyses of compounds [Li(thf)₄]₂[Bi₄I₁₄(thf)₂], [Li(thf)₄]₄[Bi₅I₁₉], [Na(thf)₆]₄[Bi₆I₂₂] and (Ph₄P)₄[Bi₆I₂₂] are described. The anions of these compounds consist of edge-sharing BiI₆ and BiI₅(thf) octahedra. The Bi atoms lie in a plane and are coordinated by bridging and terminal I atoms and by THF ligands in a distorted octahedral fashion. [Li(thf)₄]₂[Bi₄I₁₄(thf)₂]: Space group P1 (No. 2), a = 1 159.9(6), b = 1 364.6(7), c = 1 426.5(7) pm, α = 114.05(3), β = 90.01(3), γ = 100.62(3)°. [Li(thf)₄]₄[Bi₅I₁₉]: Space group P2₁/n (No. 14), a = 1 653.0(9), b = 4 350(4), c = 1 836.3(13) pm, β = 114.70(4)°. [Na(thf)₆]₄[Bi₆I₂₂]: Space group P2₁/n (No. 14), a = 1 636.4(3), b = 2 926.7(7), c = 1 845.8(4) pm, β = 111.42(2)°. (Ph₄P)₄[Bi₆I₂₂]: Space group P1 (No. 2), a = 1 368.6(7), b = 1 508.1(9), c = 1 684.9(8) pm, α = 98.28(4), β = 95.13(4), γ = 109.48(4)°.     

THE MOLECULAR AND CRYSTAL STRUCTURE OF [Et4N]2[Fe2S2（NO）4]

<正> The compound [Et_4N]_2[Fe_2S_2(NO)_4] (M_r=556.36) crystallizes in the monoclinic,space group P 2_1/n with a=9. 688(3), b=10. 882(2), c=12. 625(2), β=97. 86(3)°, Z=2, V=1318. 4, D_c=1. 40g/cm~3, ;μ(MoK_a)=12. 8cm~(-1) and F(000)=588. The final R=0. 028 and R_w=0. 029 for 2041 reflections (I≥3σ(I)).The crystals of [Et_4N]_2[Fe_2S_2(NO)_4] consist of discrete cations [Et_4N]~+ and anions     

CRYSTAL STRUCTURE OF [Et_4N]_2[Mo_2O_2(μ-S)_2(S_2)_2]

<正> [(C2H5)4N]2[Mo2o2S2(S2)2], Mr = 676. 74, monoclinic, P21/c, a = 13.510(2), b = 14.373(2), c=14. 777(3)(?), β = 97.53(2)°, V = 2844.7(9) (?)3, Z = 4, Dc= 1. 58g/cm3, μ(MoKα) = 13.0cm-1, F(000) = 1384, R =0. 033 for 1803 observed reflections. The structure contains discrete [Mo2O2S2(S2)2]2- anions and Et4N+ cations. The two oxygen atoms bonded to the Mo atoms are in cis-form with respect to the Mo2S2 bridging unit, with an average Mo- O distance of 1. 678 (?), The Mo…Mo distance is 2. 832(1)(?).     

SYNTHESIS AND STRUCTURE OF (Et_4N) [Fe_4S_4 (Et_2NCS_2)_4 ]

<正> INTRODUCTION. The Fe_4S_4 cubane-like clusters have been extensively studied as the model compounds for the active center of the Fe-S proteins in the last fifteen years. Coucouvains et al. have recently reported the syntheses and structures of a few Fe_4S_4 cluster compounds containing R_2NCS_2(R_2dtc) and RS (or Cl) mixed terminal ligands and having [Fe_4S_4]~(2+) core oxi-     

Synthesis and characterization of the silver maleonitrilediselenolates and silver maleonitriledithiolates [K([2.2.2]-cryptand)]4[Ag4(Se2C2(CN)2)4], [Na([2.2.2]-cryptand)]4[Ag4(S2C2(CN)2)4].0.33MeCN, [NBu4]4[Ag4(S2C2(CN)2)4], [K([2.2.2]-cryptand)]3[Ag(Se2C2(CN)2)2].2MeCN, and [Na([2.2.2]-cryptand)]3[Ag(S2C2(CN)2)2

Reaction of AgBF(4), KNH(2), K(2)Se, Se, and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)](4)[Ag(4)(Se(2)C(2)(CN)(2))(4)] (1). In the unit cell of 1 there are four [K([2.2.2]-cryptand)](+) units and a tetrahedral Ag(4) anionic core coordinated in mu(1)-Se, mu(2)-Se fashion by each of four mns ligands (mns = maleonitrilediselenolate, [Se(2)C(2)(CN)(2)](2)(-)). Reaction of AgNO(3), Na(2)(mnt) (mnt = maleonitriledithiolate, [S(2)C(2)(CN)(2)](2)(-)), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)](4)[Ag(4)(mnt)(4)].0.33MeCN (2). The Ag(4) anion of 2 is analogous to that in 1. Reaction of AgNO(3), Na(2)(mnt), and [NBu(4)]Br in acetonitrile yields [NBu(4)](4)[Ag(4)(mnt)(4)] (3). The anion of 3 also comprises an Ag(4) core coordinated by four mnt ligands, but the Ag(4) core is diamond-shaped rather than tetrahedral. Reaction of [K([2.2.2]-cryptand)](3)[Ag(mns)(Se(6))] with KNH(2) and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)](3)[Ag(mns)(2)].2MeCN (4). The anion of 4 comprises an Ag center coordinated by two mns ligands in a tetrahedral arrangement. Reaction of AgNO(3), 2 equiv of Na(2)(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)](3)[Ag(mnt)(2)] (5). The anion of 5 is analogous to that of 4. Electronic absorption and infrared spectra of each complex show behavior characteristic of metal-maleonitriledichalcogenates. Crystal data (153 K): 1, P2/n, Z = 2, a = 18.362(2) A, b = 16.500(1) A, c = 19.673(2) A, beta = 94.67(1) degrees, V = 5941(1) A(3); 2, P4, Z = 4, a= 27.039(4) A, c = 15.358(3) A, V = 11229(3) A(3); 3, P2(1)/c, Z = 6, a = 15.689(3) A, b = 51.924(11) A, c = 17.393(4) A, beta = 93.51(1) degrees, V = 14142(5) A(3); 4, P2(1)/c, Z = 4, a = 13.997(1) A, b = 21.866(2) A, c = 28.281(2) A, beta = 97.72(1) degrees, V = 8578(1) A(3); 5, P2/n, Z = 2, a = 11.547(2) A, b = 11.766(2) A, c = 27.774(6) A, beta = 91.85(3) degrees, V = 3772(1) A(3).     

The Binary Group 4 Azides [PPh4]2[Zr(N3)6] and [PPh4]2[Hf(N3)6]

The binary zirconium and hafnium polyazides [PPh₄]₂[M(N₃)₆] (M=Zr, Hf) were obtained in near quantitative yields from the corresponding metal fluorides MF₄ by fluoride–azide exchange reactions with Me₃SiN₃ in the presence of two equivalents of [PPh₄][N₃]. The novel polyazido compounds were characterized by their vibrational spectra and their X‐ray crystal structures. Both anion structures provide experimental evidence for near‐linear M‐N‐N coordination of metal azides. The species [M(N₃)₄], [M(N₃)₅]^? and [M(N₃)₆]^2? (M=Ti, Zr, Hf) were studied by quantum chemical calculations at the electronic structure density functional theory and MP2 levels.     

1-D and 2-D homoleptic dicyanamide structures, [Ph4P]2[CoII[N(CN)2]4] and [Ph4P][M[N(CN)2]3] (M = Mn, Co)

The homoleptic complexes [Ph(4)P](2)[Co[N(CN)(2)](4)] and [Ph(4)P][M[N(CN)(2)](3)] [M = Co, Mn] have been structurally as well as magnetically characterized. The complexes containing [M[N(CN)(2)](4)](2-) form 1-D chains, which are bridged via a common dicyanamide ligand in [M[N(CN)(2)](3)](-) to form a 2-D structure. The five-atom [NCNCN](-) bridging ligands lead to weak magnetic coupling along a chain. The six [NCNCN](-) ligands lead to a (4)T(1g) ground state for Co(II) which has an unquenched spin-orbit coupling that is reflected in the magnetic properties. Long-range magnetic ordering was not observed in any of these materials.     

Two new [Ni(tren)2]2+ complexes: [Ni(tren)2]Cl2 and [Ni(tren)2]WS4

Both title compounds, bis­[tris(2‐amino­ethyl)­amine]­nickel(II) dichloride, [Ni(tren)₂]Cl₂, (I), and bis­[tris(2‐amino­ethyl)­amine]­nickel(II) tetra­thio­tungstate, [Ni(tren)₂]WS₄, (II), contain the [Ni(tren)₂]²⁺ cation [tren is tris(2‐amino­ethyl)­amine, C₆H₁₈N₄]. The tren mol­ecule acts as a tridentate ligand around the central Ni atom, with the remaining primary amine group not bound to the central atom. In (I), Ni²⁺ is located on a centre of inversion surrounded by one crystallographically independent tren mol­ecule. In the [Ni(tren)₂]²⁺ cation of (II), the Ni atom is bound to two crystallographically independent tren mol­ecules. The Ni atoms in the [Ni(tren)₂]²⁺ complexes are in a distorted octahedral environment consisting of six N atoms from the chelating tren mol­ecules. The counter‐ions are chloride anions in (I) and the tetrahedral [WS₄]^2? anion in (II). Hydro­gen bonding is observed in both compounds.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN, [Ph₄P]₂[Se₂Cl₆], and [Ph₄P]₂[Se(Se₅)₂] By symproportionation of elemental selenium and SeCl₄ in polar protic solvents the novel chloroselenates(+II), [SeCl₄]^2? and [Se₂Cl₆]^2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl₄]^2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph₄P]₂[Se₂Cl₆] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se₂Cl₆]^2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se₅)₂]^2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph₄P]₂[Se(Se₅)₂] (space group P2₁/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se₅)₂]^2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se₅]_2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.