脓毒症患者炎性因子、凝血功能与APACHEⅡ评分和预后的关系

目的:研究脓毒症患者炎性因子、凝血功能与急性生理学和慢性健康状况Ⅱ(APACHEⅡ)评分和预后的关系。方法:选取2017年1月至2018年1月我院收治的脓毒症患者150例为脓毒症组,所有患者根据预后结果分为死亡组(n=49)和存活组(n=101),选择同期在我院住院的非脓毒症患者98例为非脓毒症组,比较脓毒症组与非脓毒症组患者炎性因子、凝血功能指标水平及APACHEⅡ评分,同时比较死亡组和存活组患者炎性因子、凝血功能指标水平及APACHEⅡ评分,并分析脓毒症患者APACHEⅡ评分与炎性因子、凝血功能指标的相关性。结果:脓毒症组患者降钙素原(PCT)、活化部分凝血酶原时间(APTT)、凝血酶原时间(PT)水平及APACHEⅡ评分均高于非脓毒症组,血小板计数(PLT)低于非脓毒症组(P0.05),两组C-反应蛋白(CRP)比较差异无统计学意义(P0.05)。死亡组患者PCT、APTT、PT水平及APACHEⅡ评分均高于存活组,PLT水平低于存活组(P0.05),两组CRP比较差异无统计学意义(P0.05)。经Spearman相关性分析结果显示,脓毒症患者APACHEⅡ评分与PCT、APTT、PT均呈正相关关系,与PLT呈负相关关系(P0.05),与CRP无相关性(P0.05)。结论:脓毒症患者PCT、APTT、PT水平明显上升,PLT水平明显下降,且均与患者的APACHEⅡ评分密切相关,临床可通过调节炎症因子水平及凝血功能指标从而改善患者的病情和预后。     

血清降钙素原、乳酸清除率及危重疾病评分对脓毒症预后的评估价值

目的:探讨血清降钙素原(procalcitonin,PCT)、乳酸清除率及危重疾病评分(Acute Physiology and Chronic Health EvaluationⅡ,APACHEⅡ)对脓毒症预后的评估价值。方法:选择2011年2月~2013年2月期间我院收治的脓毒症休克及严重脓毒症患者92例,其中脓毒症休克37例,严重脓毒症者55例;存活60例,死亡32例。对本组患者血清PCT、乳酸清除率及APACHEⅡ进行分析,探讨以上指标对其预后的评定价值。结果:1死亡组血清PCT、APACHEⅡ、乳酸分值均大于存活组,左心射血分数(Left ventricular ejection fraction,LVEF)及早期乳酸清除率小于存活组,对比具有统计学意义(P0.01或P0.05);2脓毒性休克组血清PCT、APACHEⅡ、乳酸分值均大于严重脓毒症组,LVEF及早期乳酸清除率小于严重脓毒症组,对比具有统计学意义(P0.01或P0.05);3本组乳酸与APACHEⅡ呈正相关性(P0.01),早期乳酸清除率与APACHEⅡ呈负相关性(P0.01)。结论:PCT、乳酸清除率及APACHEⅡ评分可以作为脓毒血症预后的有效评估指标,通过对PCT、乳酸清除率及APACHEⅡ评分监测以便尽早采取积极的治疗措施,改善预后情况。     

脓毒症患者血清HMGB1、IGF-1水平变化及与T淋巴细胞亚群、预后的关系研究

目的:探讨脓毒症患者血清高迁移率族蛋白1(HMGB1)、胰岛素样生长因子-1(IGF-1)水平变化及与T淋巴细胞亚群、预后的关系。方法:选取2016年2月～2018年12月期间我院收治的脓毒症患者139例,根据Sepsis 3.0定义,将脓毒症患者分成一般脓毒症组(n=73)及脓毒症休克组(n=66),根据患者进入重症监护室28d后的转归资料,将其分为存活组和死亡组。比较不同预后、不同病情严重程度的脓毒症患者血清IGF-1、HMGB1水平、急性病生理与慢性健康评价系统Ⅱ(APACHEⅡ)评分以及T淋巴细胞亚群;采用Pearson相关分析血清HMGB1、IGF-1水平与T淋巴细胞亚群、APACHEⅡ评分的关系。结果:一般脓毒症组CD3~+、CD4~+、CD4~+/CD8~+高于脓毒症休克组,CD8~+低于脓毒症休克组(P0.05)。脓毒症休克组血清HMGB1水平、APACHEⅡ评分均高于一般脓毒症组,血清IGF-1水平则低于一般脓毒症组(P0.05)。存活组CD8~+低于死亡组,CD3~+、CD4~+、CD4~+/CD8~+高于死亡组(P0.05)。存活组血清HMGB1水平、APACHEⅡ评分低于死亡组,血清IGF-1水平高于死亡组(P0.05)。Pearson相关分析显示,脓毒症患者血清HMGB1水平与CD8~+、APACHEⅡ评分呈正相关,与CD3~+、CD4~+、CD4~+/CD8~+呈负相关(P0.05);血清IGF-1水平与CD8~+、APACHEⅡ评分呈负相关,与CD3~+、CD4~+、CD4~+/CD8~+呈正相关(P0.05)。结论:脓毒症血清HMGB1、T淋巴细胞亚群、IGF-1均存在异常变化,可用于评估脓毒症患者的病情和预后。     

脓毒症患者血清FGF-21、MR-proADM、炎性因子与预后的关系分析

目的:探讨血清人成纤维细胞生长因子-21(FGF-21)、肾上腺髓质素前体中段肽(MR-proADM)、炎性因子与脓毒症患者预后的关系。方法:选取2015年9月至2018年9月我院收治的脓毒症患者160例(脓毒症组),按病情严重程度分为轻度脓毒症组(A组)56例、严重脓毒症组(B组)53例,脓毒性休克组(C组)51例,另选取同期50例健康体检者作为健康对照组。检测各组血清FGF-21、MR-proADM和炎性因子[(白细胞(WBC),白细胞介素-6(IL-6),肿瘤坏死因子-α(TNF-α),白细胞介素-10(IL-10)]水平,记录脓毒症患者序贯性器官功能衰竭评分(SOFA)和急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分及28 d预后。采用受试者工作特征(ROC)曲线分析FGF-21、MR-proADM、炎性因子单独及联合评估脓毒症预后的价值。采用Spearman相关分析FGF-21、MR-proADM和炎性因子与APACHEⅡ评分、SOFA评分的相关性。结果:脓毒症组血清FGF-21、MR-proADM和炎性因子WBC、IL-6、TNF-α、IL-10水平均明显高于健康对照组(均P0.05),且随着脓毒症病情的加重,患者血清FGF-21、MR-proADM和炎性因子水平逐渐升高。脓毒症患者中28d死亡43例(26.88%),其中A组8例(14.29%)、B组12例(22.64%)、C组23例(45.10%)。ROC曲线分析显示,联合检测评估脓毒症患者病死率的曲线下面积(AUC)、敏感度及特异度均高于单一检测。脓毒症患者血清FGF-21、MR-proADM、WBC、IL-6、TNF-α与APACHEⅡ评分及SOFA评分均呈正相关性(P0.05),此外,IL-10与SOFA评分呈正相关性(P0.05),与APACHEⅡ评分无相关性(P0.05)。结论:脓毒症患者血清FGF-21、MR-proADM水平升高,检测FGF-21、MR-proADM和炎性因子有助于评估脓毒症患者的病情及预后。     

血清sTM、PCT、CRP/PAB比值与脓毒症患者APACHEⅡ评分、SOFA评分的相关性及其联合检测对预后的预测价值

摘要 目的：探讨血清可溶性血栓调节蛋白（sTM）、降钙素原（PCT）、C-反应蛋白与前白蛋白（CRP/PAB）比值与脓毒症患者急性生理和慢性健康评估Ⅱ（APACHEⅡ）评分、序贯器官衰竭评估（SOFA）评分的相关性及其联合检测对预后的预测价值。方法：选取2020年3月～2020年12月我院重症医学科收治的97例脓毒症患者,根据Sepsis-3.0诊断标准分为普通脓毒症组44例、脓毒性休克组53例,根据入院后30 d内预后情况分为死亡组35例和存活组62例。收集患者基线资料和APACHEⅡ评分、SOFA评分,并检测血清sTM、PCT、CRP/PAB比值。采用Spearman相关性分析脓毒症患者血清sTM、PCT、CRP/PAB比值与APACHEⅡ评分、SOFA评分的相关性,多因素Logistic回归分析脓毒症患者预后不良的影响因素,受试者工作特征（ROC）曲线分析血清sTM、PCT、CRP/PAB比值对脓毒症患者预后不良的预测价值。结果：脓毒性休克组血清sTM、PCT、CRP/PAB比值和APACHEⅡ评分、SOFA评分高于普通脓毒症组（P均＜0.05）。Spearman相关性分析显示,脓毒症患者血清sTM、PCT、CRP/PAB比值与APACHEⅡ评分、SOFA评分呈正相关（P＜0.05）。多因素Logistic回归分析显示,收缩压升高为脓毒症患者预后不良的独立保护因素（P＜0.05）,脓毒性休克、合并器官损伤≥3个、机械通气时间延长、APACHEⅡ评分增加、SOFA评分增加、sTM升高、PCT升高、CRP/PAB比值升高为独立危险因素（P均＜0.05）。ROC曲线分析显示,血清sTM、PCT、CRP/PAB比值联合预测脓毒症患者预后不良的曲线下面积大于各指标单独预测。结论：脓毒症患者血清sTM、PCT、CRP/PAB比值升高与APACHEⅡ评分、SOFA评分增加密切相关,血清sTM、PCT、CRP/PAB比值联合检测对脓毒症患者预后不良的预测价值较高。     

不同分级及转归脓毒症患者血清PCT、D-D、CRP及血小板相关参数检测的临床意义

目的:探讨不同分级及转归脓毒症患者的血清降钙素原(PCT)、D-二聚体(D-D)、C反应蛋白(CRP)及血小板相关参数检测的临床意义。方法:回顾性分析2015年3月至2018年8月期间中国人民解放军西部战区总医院收治的92例脓毒症患者的临床资料,分析不同分级及转归脓毒症患者的血清中PCT、D-D和CRP水平、急性病生理与慢性健康评价系统Ⅱ(APACHEⅡ)评分及血小板相关参数[血小板计数(PLT)、血小板平均容积(MPV)、血小板分布宽度(PDW)、大型血小板比率(P-LCR)],并分析脓毒症患者PCT、D-D、CRP水平以及血小板相关参数与APACHEⅡ评分的相关性。结果:全身炎症反应综合征组、轻度脓毒症组、严重脓毒症组、脓毒性休克组血清PCT、D-D和CRP水平、MPV、PDW、P-LCR、APACHEⅡ评分逐渐升高(P0.05),PLT逐渐降低(P0.05)。存活组患者血清PCT、D-D、CRP水平、MPV、PDW、P-LCR、APACHEⅡ评分均低于死亡组(P0.05),PLT高于死亡组(P0.05)。Pearson相关分析显示,脓毒症患者血清PCT、D-D、CRP、MPV、PDW、P-LCR与APACHE II评分呈正相关(P0.05),PLT与APACHE II评分呈负相关(P0.05)。结论:脓毒症患者血清PCT、D-D、CRP及血小板相关指标可能参与了脓毒症的发展,通过检测其血清PCT、D-D、CRP水平及血小板相关参数可评估脓毒症患者的病情和预后。     

血清CHE、LDH及 APACHEⅡ评分与重症肺炎患者病情变化的关系及其在临床预后中的价值

摘要 目的：探讨血清胆碱酯酶（CHE）和乳酸脱氢酶（LDH）水平、急性生理学及慢性健康状况评分（APACHE Ⅱ）与重症肺炎患者病情变化的关系以及对患者预后评估的价值。方法：回顾性分析本院呼吸与危重症医学科在2019年7月至2022年6月期间收治的88例重症肺炎患者、96例普通肺炎患者和同期来院体检的100名健康者的临床资料。根据是否死亡将重症肺炎患者分为存活组（58例）和死亡组（30例）。采用丁酰硫代胆碱底物法检测血清CHE水平,采用乳酸底物法检测血清LDH水平,测量入院时APACHE Ⅱ评分并进行统计分析。采用受试者工作特征（ROC）曲线分析患者血清CHE、LDH水平和APACHE Ⅱ评分对死亡的预测价值。结果：（1）重症肺炎组血清CHE水平显著低于普通肺炎组和对照组,LDH水平显著高于普通肺炎组和对照组,APACHE Ⅱ评分显著高于普通肺炎组（P<0.05）。普通肺炎组血清CHE水平与对照组比较无差异（P>0.05）,LDH水平显著高于对照组（P<0.05）。（2）存活组患者血清CHE水平随时间显著增加,LDH水平和APACHE Ⅱ评分显著降低;死亡组患者血清CHE水平随时间显著降低,LDH水平和APACHE Ⅱ评分显著增加（P<0.05）。死亡组患者不同时间血清CHE水平显著低于存活组,LDH水平和APACHE Ⅱ评分显著高于存活组（P<0.05）。（3）重症肺炎患者血清CHE与LDH和APACHE Ⅱ评分间均呈显著负相关,LDH和APACHE Ⅱ评分呈显著正相关（P<0.05）。（4）ROC曲线结果表明：入院第1d血清CHE预测重症肺炎患者死亡的AUC为0.790（95%CI：0.688~0.891）,最佳诊断cutoff值为≤3.3 kU/L,对应的敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为66.67%、77.59%、44.26%、60.61%和81.82%;血清LDH预测重症肺炎患者死亡的AUC为0.924（95%CI：0.862~0.985）,最佳诊断cutoff值为≥382 U/L,对应的敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为93.33%、79.31%、72.64%、70.00%和95.83%。APACHE Ⅱ评分预测重症肺炎患者死亡的AUC为0.966（95%CI：0.931~1.000）,最佳诊断cutoff值为≥23.5分,对应的敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为83.33%、100.00%、83.33%、100.00%和92.06%。结论：入院第1 d时血清CHE、LDH和APACHE Ⅱ评分都能有效预测重症肺炎发生死亡的风险,LDH和APACHE Ⅱ评分预测效能更高,且LDH操作更加简单。     

降钙素原联合SOFA评分对老年脓毒症患者预后的评估价值

目的:探讨降钙素原(procalcitonin,PCT)联合SOFA评分(sequential organ failure assessment,SOFA)对老年脓毒症患者预后的评估价值。方法:选择首都医科大学宣武医院急诊抢救室收治的105例老年脓毒症患者,入院后给予血常规、血清PCT水平、血气分析及生化全项等检查,并进行急性生理及慢性健康状况评分(acute physiology and chronic health evaluation,APACHEⅡ)和SOFA评分。根据预后将患者分成死亡组27例和存活组78例,比较两组组患者血清PCT水平、白细胞(WBC)、SOFA评分和APACHEⅡ评分,同时比较和分析APACHEⅡ评分、血清PCT水平、SOFA评分、PCT和SOFA评分联合预测患者死亡的受试者工作特征曲线(Receiver operating characteristic curve,ROC)下面积。结果:死亡组患者血清PCT水平、SOFA评分和APACHEⅡ评分均明显高于存活组(P0.05),两组WBC比较无统计学差异(P=0.132);PCT预测患者死亡的ROC曲线下面积为0.694(P=0.001),SOFA预测患者死亡的ROC曲线下面积为0.660(P=0.012),APACHE II评分预测患者死亡的ROC曲线下面积为0.852(P=0.001),大于PCT和SOFA评分(P0.05),PCT和SOFA评分联合预测患者死亡的ROC曲线下面积0.761(P=0.001),与APACHE II评分比较无统计学差异(P=0.139)。结论:血清PCT水平联合SOFA评分预测老年脓毒症患者预后的临床价值与APACHE II评分相当,均明显优于血清PCT水平和SOFA评分单项检测。     

血清尿调节素、肝素结合蛋白、Klotho蛋白联合APACHEⅡ评分对脓毒症并发急性肾损伤患者28天预后的评估价值

摘要 目的：探讨血清尿调节素（UMOD）、肝素结合蛋白（HBP）、Klotho蛋白联合急性生理和慢性健康状况评估系统Ⅱ（APACHEⅡ）评分预测脓毒症并发急性肾损伤(AKI)患者28天预后的价值。方法：选取2018年1月至2020年1月期间我院诊治的脓毒症并发AKI患者120例作为研究对象,根据28天以内的生存情况分为存活组(86例)和死亡组(34例)。采用酶联免疫吸附实验检测各组血清UMOD、HBP、Klotho蛋白表达水平。比较不同分期的AKI患者血清UMOD、HBP、Klotho蛋白表达及APACHEⅡ评分差异。多因素Logistic回归分析影响脓毒症并发AKI患者28天预后的危险因素。应用受试者工作特征(ROC)曲线分析血清UMOD、HBP、Klotho蛋白及APACHEⅡ评分单独及联合预测脓毒症并发AKI患者28天预后的价值。结果：相比于存活组,死亡组患者血清UMOD、Klotho较低,降钙素原（PCT）、超敏C反应蛋白（hs-CRP）、HBP、APACHEⅡ评分较高 (P均<0.05)。不同AKI分期患者血清UMOD、HBP、Klotho及APACHEⅡ评分差异具有统计学意义(P均<0.05)。多因素Logistic回归分析显示UMOD＜62.43 mg/mL、HBP＞30.14 μg/L、Klotho≤180.37 ng/L、APACHEⅡ评分＞16.00分是影响患者28天死亡预后的危险因素。血清UMOD、HBP、Klotho、APACHEⅡ评分四者联合预测脓毒症并发AKI患者28天死亡的曲线下面积为0.897(0.842～0.939),明显高于血清UMOD[0.724(0.674～0.765)]、HBP[0.666(0.622～0.710)]、Klotho[0.767(0.731～0.804)]、APACHEⅡ评分[0.840(0.802～0.878)]单一检测 。结论：脓毒症并发AKI患者血清UMOD、Klotho降低,HBP水平升高且APACHEⅡ评分较高,与脓毒症并发AKI患者的病情严重程度有关,四者联合能辅助预测脓毒症并发AKI患者28天死亡。     

脓毒症患者发生凝血功能紊乱的临床特征及预后影响因素分析

摘要 目的：探究脓毒症患者发生凝血功能紊乱的临床特征及预后影响因素。方法：选择2019年9月~2023年1月本院收治的80例脓毒症患者为本次研究对象,对所有患者开展凝血功能检验,并依据检验结果,将患者分为凝血功能异常组（n=60）及正常组（n=20）,分析凝血功能障碍异常及正常患者临床特征、凝血功能障碍异常及正常患者病情严重程度,并依据脓毒症患者预后,将其分为存活组（n=64）及死亡组（n=16）脓毒症患者预后的单因素与多因素Logistic回归分析。结果：凝血功能正常组及异常组平均动脉压、体温、白细胞计数（WBC）、纤维蛋白原（FIB）、凝血酶时间（TT）指标水平无较大差异（P＞0.05）,与凝血功能正常组比较,凝血功能异常组患者呼吸、脉率、降钙素原（PCT）、C反应蛋白（CRP）指标水平相对较高,部分凝血活酶时间（APTT）、凝血酶原时间（PT）指标水平相对较长,PLT指标水平相对较高（P＜0.05）;与凝血功能正常的脓毒症患者相比较,凝血功能异常患者急性肾损伤（AKI）及急性呼吸窘迫综合征（ARDS）发生率、急性生理与慢性健康评分（APACHE Ⅱ）及急性生理功能评分（SOFA）评分更高,住ICU时间均相对较长（P＜0.05）,机械通气及住院时间比较（P＞0.05）;脓毒症患者预后影响因素分析中,结果显示,年龄、体质量指数（BMI）、性别、糖尿病史、高血压病史均未对脓毒症患者预后产生较大影响（P＞0.05）,PT、PCT、APTT、CRP、SOFA评分及APACHE Ⅱ评分对脓毒症预后产生严重影响,死亡组患者各指标水平均高于存活组（P＜0.05）;将影响脓毒症患者预后的单因素予以赋值,纳入Logistic回归分析,以PCT、PT、APTT、CRP、SOFA、APACHE Ⅱ 评分为自变量,结果显示,PCT、PT、CRP、SOFA、APACHE Ⅱ 评分是影响脓毒症患者预后的独立危险因素（P＜0.05）。结论：脓毒症患者发生凝血功能紊乱会对临床相关指标产生影响,从而增加疾病严重程度,依据脓毒症患者预后,研究结果显示,PT、PCT、CRP、SOFA及APACHE Ⅱ评分均会对脓毒症患者预后产生不良影响,检验上述指标水平,可为临床评估脓毒症预后提供一定参考价值。     

Pressure-tuning infrared and Raman spectra of trans-dichloro-bis[(diperfluoroethyl)phenylphosphine]platinum(II), trans-Pt[PPh(CF3CF2)2]2Cl2

Infrared and Raman spectra of solid trans-dichloro-bis[diperfluoroethyl(phenyl)phosphine]platinum(II), trans-Pt[PPh(CF₃CF₂)₂]₂Cl₂, have been studied at high external pressures up to ∼50 kbar with the aid of a diamond-anvil cell. A gradual, pressure-induced phase transition, most probably second order, was observed in the 21-34 kbar pressure range. In the IR spectra, the bands assigned to the CF stretching modes of the CF₃ groups exhibit larger pressure sensitivities than do those associated with the CF stretching modes of the CF₂ groups, most probably because of their physical location on the outside in the molecules in the unit cell. The fairly high pressure sensitivities of the symmetric PtCl stretching mode in both the low and high pressure phases (0.46 and 37 cm⁻¹/kbar, respectively) are considered to reflect the low force constant associated with the long PtCl bond length thus making this vibration more susceptible to compression.     

Effect of Iron Chelators on Dopamine D2 Receptors

Nutritional iron deficiency induced in rats causes a selective reduction of [3H]spiperone binding in caudate nucleus. This effect can be reversed by iron supplementation in vivo. The possibility that iron may be involved in the dopamine D2 receptor was investigated by examining the effect of various iron and noniron chelators on the binding of [3H]spiperone in rat caudate nucleus. Iron chelators 1,10-phenanthroline, 2,4,6-tripyridyl-s-triazine, alpha, alpha'-dipyridyl, and desferrioxamine mesylate inhibited the binding of [3H]spiperone. The inhibition by 1,10-phenanthroline was noncompetitive and reversible. In the presence of FeCl2 or FeCl3, the inhibitory effect of 1,10-phenanthroline was potentiated. Iron salts or chelators were without effect on the binding of [3H]dihydroalprenolol to beta-adrenoreceptors in caudate nucleus; thus the action of iron chelators on the dopamine D2 receptor tends to be selective. Incubation of caudate nucleus membrane prepared from iron-deficient rats with FeCl2 or FeCl3 did not reverse the diminished binding of [3H]spiperone. The present study indicates that if iron is involved in the physiological regulation of dopamine D2 agonist-antagonist binding sites, it is more complex than hitherto considered.     

Kinetic studies on the first dihydrogen aquacomplex, [Ru(H2)(H2O)5]: Formation under H2 pressure and catalytic H/D isotope exchange in water

The ruthenium(II) hexaaqua complex [Ru(H₂O)₆]²⁺ reacts with dihydrogen under pressure to give the η²-dihydrogen ruthenium(II) pentaaqua complex [Ru(H₂)(H₂O)₅]²⁺.The complex was characterized by ¹H, ²H and ¹⁷O NMR: δ_H = −7.65 ppm, J_HD = 31.2 Hz, δ_O = −80.4 ppm (trans to H₂) and δ_O = −177.4 ppm (cis to H₂).The H-H distance in coordinated dihydrogen was estimated to 0.889 Å from J_HD, which is close to the value obtained from DFT calculations (0.940 Å).Kinetic studies were performed by ¹H and ²H NMR as well as by UV-Vis spectroscopy, yielding the complex formation rate and equilibrium constants: k_f = (1.7 ± 0.2) × 10⁻³ kg mol⁻¹ s⁻¹ and K_eq = 4.0 ± 0.5 mol kg⁻¹.The complex formation rate with dihydrogen is close to values reported for other ligands and thus it is assumed that the reaction with dihydrogen follows the same mechanisn (I_d).In deuterated water, one can observe that [Ru(H₂)(H₂O)₅]²⁺ catalyses the hydrogen exchange between the solvent and the dissolved dihydrogen.A hydride is proposed as the intermediate for this exchange.Using isotope labeling, the rate constant for the hydrogen exchange on the η²-dihydrogen ligand was determined as k₁ = (0.24 ± 0.04) × 10⁻³ s⁻¹.The upper and lower limits of the pK_a of the coordinated dihydrogen ligand have been estimated:3 < pK_a < 14.     

New preparations and molecular structures of cis-MCl2(Ph2PCH2PPh2)2, M = Ru,Os and trans-RuCl2(Ph2PCH2PPh2)2

The title compounds were made by reacting bis(diphenylphosphino)methane (dppm) with reduced solutions of OsCl₆^4? and Ru₂OCl₁₀^4?. The crystal and molecular structures of these compounds have been determined form three-dimensional X-ray study. The cis-isomers crystallize with one CHCl₃ per molecule of the complex. All three compounds crystallize in the monoclinic space group P2₁/n with unit cell dimensions as follows: Cis-OsCl₂(dppm)₂·CHCl₃: a = 13.415(4) Å, b = 22.859(4) Å, c = 16.693(3) Å, β = 105.77(3)°, V = 4926(3) ų, Z = 4. cis-RuCl₂(dppm)₂·CHCl₃: a = 13.442(3) Å, b = 22.833(7) Å, c = 16.750(4) Å, β = 105.53(2)°, V = 4953(3) ų, Z = 4. trans-RuCl₂(dppm)₂: a = 11.368(7) Å, b = 10.656(6) Å, c = 18.832(12) Å; β = 103.90(6)°, V = 2213(7) ų; Z = 2. The structures were refined to R = 0.044 (R_w = 0.055) for cis-OsCl₂(dppm)₂·CHCl₃; R = 0.065 (R_w = 0.079) for cis-RuCl₂(dppm)₂·CHCl₃ and R = 0.028 (R_w = 0.038) for trans-RuCl₂(dppm)₂. The complexes are six coordinate with stable four-membered chelate rings. The PMP angle in the chelate rings is ca. 71° in each case.     

Synthesis of tantalum and niobium complexes that contain the diamidoamine ligand, [(3,4,5-F3C6H2NCH2CH2)2NMe], and the triamidoamine ligand, [(3,5-Cl2C6H3NCH2CH2)3N]

Several niobium and tantalum compounds were prepared that contain either the diamidoamine ligand, [(3,4,5-F₃C₆H₂NCH₂CH₂)₂NMe]²⁻ ([F₃N₂NMe]²⁻), or the triamidoamine ligand, [(3,5-Cl₂C₆H₃NCH₂CH₂)₃N]³⁻ ([Cl₂N₂NMe]³⁻). The former include [F₃N₂NMe]TaCl₃, [F₃N₂NMe]NbCl₃, [F₃N₂NMe]TaMe₃, [F₃N₂NMe]NbMe₃, [(F₃N₂NMe)TaMe₂][MeB(C₆F₅)₃], [F₃N₂NMe]Ta(CHSiMe₃)(CH₂SiMe₃), [F₃N₂NMe]Ta(CH₂-t-Bu)Cl₂, [F₃N₂NMe]Ta(CH-t-Bu)(CH₃), and [F₃N₂NMe]Ta(η²-C₂H₄)(CH₂CH₃). The latter include [Cl₂N₂NMe]TaCl₂, [Cl₂N₂NMe]TaMe₂, [Cl₂N₂NMe]Ta(η²-C₂H₄), and [Cl₂N₂NMe]Ta(η²-C₂H₂).X-ray diffraction studies were carried out on [F₃N₂NMe]Ta(CHSiMe₃)(CH₂SiMe₃), [F₃N₂NMe]Ta(η²-C₂H₄)(CH₂CH₃), and [Cl₂N₂NMe]TaMe_2..     

Crystal structures of MoCl2(O)(O2)(OPMePh2)2 and mixtures of MoCl2(O2)(OPPh3)2 and MoCl2(O)(O2)(OPPh3)2: allylic alcohol isomerization studies using MoCl2(O)(O2)(OPMePh2)2

Adding one equivalent of H₂O₂ to compounds of stoichiometry MoCl₂(O)₂(OPR₃)₂, OPR₃ = OPMePh₂ or OPPh₃, leads to the formation of oxo-peroxo compounds MoCl₂(O)(O₂)(OPR₃)₂. The compound MoCl₂(O)(O₂)(OPMePh₂)₂ crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands, as verified by single-crystal X-ray diffractometry, and can be isolated in reasonable yields. MoCl₂(O)(O₂)(OPPh₃)₂, was not isolated in pure form, co-crystallized with MoCl₂(O)₂(OPPh₃)₂ in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols. A mechanism of this reaction has been constructed based on ¹⁸O isotopic studies and involves exchange between the alcohol and metal bonded O atoms.     

Synthesis and crystal structure of the MgCl2(CH3COOC2H5)2· (CH3COOC2H5) adduct

The reaction of α-MgCl₂ with boiling ethyl acetate affords MgCI₂(CH₃COOC₂H₅)₂· (CH₃COOC₂H₅), which is obtained as crystals suitable for X-ray analysis only from the mother liquor. M=315.5, orthorhombic, space group P2₁22₁ (No. 18), a=25.077(3), b=8.616(1), c=7.345(1) Å, V=1587.0(3) ų, Z=4, D_x=1.32 g cm⁻³,λ A(Mo Kα)=0.71069 Å, μ=4.17 cm⁻¹, F(000)=664, T=298 K, observed reflections: 1667, R=0.059 and R_w=0.069. The structure is composed of polymeric chains of MgCl₂(CH₃COOC₂H₅₎₂ and the ethyl acetate molecules occupy a mutually trans position.     

Achiral internucleoside linkages: CH2-CH2-NH and nH-CH2-CH2 linkages

The synthesis of CH₂-CH₂-NH and NH-CH₂-CH₂ internucleoside linkages are described. Antisense oligonucleosides containing these dimer modifications hybridized to the sense sequence. Furthermore incorporation of these backbone modifications enhanced the nuclease resistance of the antisense strand.     

Selective synthesis of triangular cluster oxido-sulfidocomplexes of Mo and W: High yield preparations of [Mo3O2S2(H2O)9], [W3O2S2(H2O)9], [W2MoO2S2(H2O)9] and their derivatization

Reaction of [Mo₂O₂(μ-S)₂(H₂O)₆]²⁺ with Mo(CO)₆ or metallic Mo under hydrothermal conditions (140 °C, 4 M HCl) gives oxido-sulfido cluster aqua complex [Mo₃(μ₃-S)(μ-O)₂(μ-S)(H₂O)₉]⁴⁺ (1). Similarly, [W₃(μ₃-S)(μ-O)₂(μ-S)(H₂O)₉]⁴⁺ (2) is obtained from [W₂O₂(μ-S)₂(H₂O)₆]²⁺ and W(CO)₆. While reaction of [Mo₂O₂(μ-S)₂(H₂O)₆]²⁺ with W(CO)₆ mainly proceeds as simple reduction to give 1, [W₂O₂(μ-S)₂(H₂O)₆]²⁺ with Mo(CO)₆ produces new mixed-metal cluster [W₂Mo(μ₃-S)(μ-O)₂(μ-S)(H₂O)₉]⁴⁺ (3) as main product. From solutions of 1 in HCl supramolecular adduct with cucurbit[6]uril (CB[6]) {[Mo₃O₂S₂(H₂O)₆Cl₃]₂CB[6]}Cl₂⋅18H₂O (4) was isolated and structurally characterized. The aqua complexes were converted into acetylacetonates [M₃O₂S₂(acac)₃(py)₃]PF₆ (M₃ = Mo₃, W₃, W₂Mo; 5a-c), which were characterized by X-ray single crystal analysis, electrospray ionization mass spectrometry and ¹H NMR spectroscopy. Crystal structure of (H₅O₂)(Me₄N)₄[W₃(μ₃-S)(μ₂-S)(μ₂-O)₂(NCS)₉] (6), obtained from 2, is also reported.