Kristallstrukturen der iso‐Thiocyanatoberyllate (Ph4P)2[Be(NCS)4] und (Ph4P)4[{Be2(NCS)4(μ‐NCS)2}{Be2(NCS)6(μ‐H2N2C2S2)}] |
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Authors: | Bernhard Neumüller Kurt Dehnicke Prof Dr |
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Institution: | Fachbereich Chemie der Philipps‐Universit?t Marburg, Hans‐Meerwein‐Stra?e, 35032 Marburg, Germany |
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Abstract: | Bis(tetraphenylphosphonium) hexachloridodiberyllate, (Ph4P)2Be2Cl6], reacts with excess trimethylsilyl‐iso‐thiocyanate to give a mixture of colourless single crystals of (Ph4P)2Be(NCS)4] ( 1 ) and (Ph4P)4{Be2(NCS)4(μ‐NCS)2}{Be2(NCS)6(μ‐H2N2C2S2)}] ( 2 ), which can be separated by selection. Both complexes were characterized by X‐ray diffraction. Compound 1 can be prepared without by‐products by treatment of (Ph4P)2BeCl4] with excess Me3SiNCS in dichloromethane solution. 1 : Space group I41/a, Z = 4, lattice dimensions at 100(2) K: a = b = 1091.2(1), c = 3937.1(3) pm, R1 = 0.0474. The Be(NCS)4]2– ion of 1 forms tetragonally distorted tetrahedral anions with Be–N distances of 168.4(2) pm and weak intermolecular S ··· S contacts along 100] and 010]. 2 ·4CH2Cl2: Space group P , Z = 1, lattice dimensions at 100(2) K: a = 919.5(1), b = 1248.3(1), c = 2707.0(2) pm, α = 101.61(1) °, β = 95.08(1) °, γ = 94.52(1) °, R1 = 0.103. Compound 2 contains two different anionic complexes in the ratio 1:1. In {Be2(NCS)4(μ‐NCS)2}2–, the beryllium atoms are connected by (NCS)– bridging groups forming centrosymmetric eight‐membered Be2(NCS)2 rings with distances Be–N of 168(1) pm and Be–S of 235.2(9) pm. The second anion {Be2(NCS)6(μ‐H2N2C2S2)}2– consists of two {Be(NCS)3}– units, which are linked by the nitrogen atoms of the unique dimeric cyclo‐addition product of HNCS with Be–N distances of 179(1) pm. |
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Keywords: | Beryllium iso‐Thiocyanates X‐ray diffraction Vibrational spectroscopy Cycloaddition |
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