The crystal structures of three unusual chromium organophosphate complexes have been determined, namely, bis(μ-butyl 2,6-di-tert-butyl-4-methylphenyl hydrogen phosphato-κO:κO')di-μ-hydroxido-bis[(butyl 2,6-di-tert-butyl-4-methylphenyl hydrogen phosphato-κO)(butyl 2,6-di-tert-butyl-4-methylphenyl phosphato-κO)chromium](Cr-Cr) heptane disolvate or {Cr2(μ2-OH)2[μ2-PO2(OBu)(O-2,6-tBu2-4-MeC6H2)-κO:κO']2[PO2(OBu)(O-2,6-tBu2-4-MeC6H2)-κO]2[HOPO(OBu)(O-2,6-tBu2-4-MeC6H2)-κO]2}·2C7H16, [Cr2(C19H32O4P)4(C19H33O4P)2(OH)2]·2C7H16, denoted (1)·2(heptane), [μ-bis(2,6-diisopropylphenyl) phosphato-1κO:2κO']bis[bis(2,6-diisopropylphenyl) phosphato]-1κO,2κO-chlorido-2κCl-triethanol-1κ2O,2κO-di-μ-ethanolato-1κ2O:2κ2O-dichromium(Cr-Cr) ethanol monosolvate or {Cr2(μ2-OEt)2[μ2-PO2(O-2,6-iPr2-C6H3)2-κO:κO'][PO2(O-2,6-iPr2-C6H3)2-κO]2Cl(EtOH)3}·EtOH, [Cr2(C2H5O)2(C24H34O4P)3Cl(C2H6O)3]·C2H6O, denoted (2)·EtOH, and di-μ-ethanolato-1κ2O:2κ2O-bis{[bis(2,6-diisopropylphenyl) hydrogen phosphato-κO][bis(2,6-diisopropylphenyl) phosphato-κO]chlorido(ethanol-κO)chromium}(Cr-Cr) benzene disolvate or {Cr2(μ2-OEt)2[PO2(O-2,6-iPr2-C6H3)2-κO]2[HOPO(O-2,6-iPr2-C6H3)2-κO]2Cl2(EtOH)2}·2C6H6, [Cr2(C2H5O)2(C24H34O4P)2(C24H35O4P)2Cl2(C2H6O)2]·2C6H6, denoted (3)·2C6H6. Complexes (1)-(3) have been synthesized by an exchange reaction between the in-situ-generated corresponding lithium or potassium disubstituted phosphates with CrCl3(H2O)6 in ethanol. The subsequent crystallization of (1) from heptane, (2) from ethanol and (3) from an ethanol/benzene mixture allowed us to obtain crystals of (1)·2(heptane), (2)·EtOH and (3)·2C6H6, whose structures have the monoclinic P21, orthorhombic P212121 and triclinic P-1 space groups, respectively. All three complexes have binuclear cores with a single Cr-Cr bond, i.e. Cr2O6P2 in (1), Cr2PO4 in (2) and Cr2O2 in (3), where the Cr atoms are in distorted octahedral environments, formally having 16 ē per Cr atom. The complexes have bridging ligands μ2-OH in (1) or μ2-OEt in (2) and (3). The organophosphate ligands demonstrate terminal κO coordination modes in (1)-(3) and bridging μ2-κO:κO' coordination modes in (1) and (2). All the complexes exhibit hydrogen bonding: two intramolecular Ophos...H-Ophos interactions in (1) and (3) form two {H[PO2(OR)2]2} associates; two intramolecular Cl...H-OEt hydrogen bonds additionally stabilize the Cr2O2 core in (3); two intramolecular Ophos...H-OEt interactions and two O...H-O intermolecular hydrogen bonds with a noncoordinating ethanol molecule are observed in (2)·EtOH. The presence of both basic ligands (OH- or OEt-) and acidic [H(phosphate)2]- associates at the same metal centres in (1) and (3) is rather unusual. Complexes may serve as precatalysts for ethylene polymerization under mild conditions, providing polyethylene with a small amount of short-chain branching. The formation of a small amount of α-olefins has been detected in this reaction.

中文翻译：

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带有双取代有机磷酸酯配体的铬配合物及其在乙烯聚合中的用途。

[Cr2（C2H5O）2（C24H34O4P）3Cl（C2H6O）3]·C2H6O，表示为（2）·EtOH，和di-ethanolato-1κ2O：2κ2O-bis{[bis（2,6-6-异丙基苯基）氢- κO] [双（2,6-二异丙基苯基）磷酸-κO]氯（乙醇-κO）铬}（Cr-Cr）苯脱溶剂或{Cr2（μ2-OEt）2 [PO2（O-2,6-iPr2- C6H3）2-κO] 2 [HOPO（O-2,6-iPr2-C6H3）2-κO] 2Cl2（EtOH）2}·2C6H6，[Cr2（C2H5O）2（C24H34O4P）2（C24H35O4P）2Cl2（C2H6O） 2]·2C6H6，表示为（3）·2C6H6。配合物（1）-（3）是通过在乙醇中原位生成的相应的二取代的锂或钾取代的磷酸锂与CrCl3（H2O）6的交换反应合成的。随后从庚烷中结晶出（1），从乙醇中结晶出（2），从乙醇/苯混合物中结晶出（3），得到的晶体为（1）·2（庚烷），（2）·EtOH和（3）· 2C6H6，其结构具有单斜P21，正交P212121和三斜P-1空间群。这三个络合物均具有带单个Cr-Cr键的双核核，即（1）中的Cr2O6P2，（2）中的Cr2PO4和（3）中的Cr2O2，其中Cr原子处于扭曲的八面体环境中，每个Cr原子正式具有16ē 。配合物在（1）中具有桥接配体μ2-OH或在（2）和（3）中具有μ2-OEt。有机磷酸酯配体在（1）-（3）中显示末端κO配位模式，在（1）和（2）中桥接μ2-κO：κO'配位模式。所有的配合物都具有氢键：（1）和（3）中的两个分子内Ophos ... H-Ophos相互作用形成两个{H [PO2（OR）2] 2}缔合体；（3）中的两个分子内Cl ... H-OEt氢键还可以稳定Cr2O2核心。两个分子内Ophos ... H-OEt相互作用和两个O ... 在（2）·EtOH中观察到与非配位乙醇分子的HO分子间氢键。在（1）和（3）的相同金属中心同时存在碱性配体（OH-或OEt-）和酸性[H（磷酸盐）2]-缔合体是非常不寻常的。在温和的条件下，络合物可以用作乙烯聚合反应的预催化剂，从而为聚乙烯提供少量的短链支化。在该反应中已经检测到少量α-烯烃的形成。